diff --git a/demo/package-lock.json b/demo/package-lock.json
index b165824..16d2844 100644
--- a/demo/package-lock.json
+++ b/demo/package-lock.json
@@ -792,6 +792,14 @@
         "qs": "6.5.1",
         "raw-body": "2.3.2",
         "type-is": "1.6.15"
+      },
+      "dependencies": {
+        "qs": {
+          "version": "6.5.1",
+          "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
+          "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A==",
+          "dev": true
+        }
       }
     },
     "boolbase": {
@@ -1346,36 +1354,44 @@
       "integrity": "sha512-STB7LZ4N0L+81FJHGla2oboUHTk4PaN1RsOkoRh9OSeEKylvF5hwKYVX1xCLFaCT7MD0BNG/gX2WFMLqY6EMBw==",
       "dev": true,
       "requires": {
-        "accepts": "1.3.4",
+        "accepts": "~1.3.4",
         "array-flatten": "1.1.1",
         "body-parser": "1.18.2",
         "content-disposition": "0.5.2",
-        "content-type": "1.0.4",
+        "content-type": "~1.0.4",
         "cookie": "0.3.1",
         "cookie-signature": "1.0.6",
         "debug": "2.6.9",
-        "depd": "1.1.1",
-        "encodeurl": "1.0.1",
-        "escape-html": "1.0.3",
-        "etag": "1.8.1",
+        "depd": "~1.1.1",
+        "encodeurl": "~1.0.1",
+        "escape-html": "~1.0.3",
+        "etag": "~1.8.1",
         "finalhandler": "1.1.0",
         "fresh": "0.5.2",
         "merge-descriptors": "1.0.1",
-        "methods": "1.1.2",
-        "on-finished": "2.3.0",
-        "parseurl": "1.3.2",
+        "methods": "~1.1.2",
+        "on-finished": "~2.3.0",
+        "parseurl": "~1.3.2",
         "path-to-regexp": "0.1.7",
-        "proxy-addr": "2.0.2",
+        "proxy-addr": "~2.0.2",
         "qs": "6.5.1",
-        "range-parser": "1.2.0",
+        "range-parser": "~1.2.0",
         "safe-buffer": "5.1.1",
         "send": "0.16.1",
         "serve-static": "1.13.1",
         "setprototypeof": "1.1.0",
-        "statuses": "1.3.1",
-        "type-is": "1.6.15",
+        "statuses": "~1.3.1",
+        "type-is": "~1.6.15",
         "utils-merge": "1.0.1",
-        "vary": "1.1.2"
+        "vary": "~1.1.2"
+      },
+      "dependencies": {
+        "qs": {
+          "version": "6.5.1",
+          "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
+          "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A==",
+          "dev": true
+        }
       }
     },
     "extglob": {
@@ -1508,7 +1524,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.1.1",
@@ -1559,7 +1576,8 @@
         "balanced-match": {
           "version": "0.4.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "bcrypt-pbkdf": {
           "version": "1.0.1",
@@ -1574,6 +1592,7 @@
           "version": "0.0.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "inherits": "2.0.3"
           }
@@ -1582,6 +1601,7 @@
           "version": "2.10.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "hoek": "2.16.3"
           }
@@ -1590,6 +1610,7 @@
           "version": "1.1.7",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "0.4.2",
             "concat-map": "0.0.1"
@@ -1598,7 +1619,8 @@
         "buffer-shims": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "caseless": {
           "version": "0.12.0",
@@ -1615,12 +1637,14 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "combined-stream": {
           "version": "1.0.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "delayed-stream": "1.0.0"
           }
@@ -1628,17 +1652,20 @@
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "cryptiles": {
           "version": "2.0.5",
@@ -1684,7 +1711,8 @@
         "delayed-stream": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "delegates": {
           "version": "1.0.0",
@@ -1710,7 +1738,8 @@
         "extsprintf": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "forever-agent": {
           "version": "0.6.1",
@@ -1732,12 +1761,14 @@
         "fs.realpath": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "fstream": {
           "version": "1.0.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "graceful-fs": "4.1.11",
             "inherits": "2.0.3",
@@ -1793,6 +1824,7 @@
           "version": "7.1.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "fs.realpath": "1.0.0",
             "inflight": "1.0.6",
@@ -1805,7 +1837,8 @@
         "graceful-fs": {
           "version": "4.1.11",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "har-schema": {
           "version": "1.0.5",
@@ -1844,7 +1877,8 @@
         "hoek": {
           "version": "2.16.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "http-signature": {
           "version": "1.1.1",
@@ -1861,6 +1895,7 @@
           "version": "1.0.6",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "once": "1.4.0",
             "wrappy": "1.0.2"
@@ -1869,7 +1904,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.4",
@@ -1881,6 +1917,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "1.0.1"
           }
@@ -1894,7 +1931,8 @@
         "isarray": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "isstream": {
           "version": "0.1.2",
@@ -1967,12 +2005,14 @@
         "mime-db": {
           "version": "1.27.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "mime-types": {
           "version": "2.1.15",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "mime-db": "1.27.0"
           }
@@ -1981,6 +2021,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "1.1.7"
           }
@@ -1988,12 +2029,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2046,7 +2089,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "oauth-sign": {
           "version": "0.8.2",
@@ -2064,6 +2108,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1.0.2"
           }
@@ -2093,7 +2138,8 @@
         "path-is-absolute": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "performance-now": {
           "version": "0.2.0",
@@ -2104,16 +2150,11 @@
         "process-nextick-args": {
           "version": "1.0.7",
           "bundled": true,
-          "dev": true
-        },
-        "punycode": {
-          "version": "1.4.1",
-          "bundled": true,
           "dev": true,
           "optional": true
         },
-        "qs": {
-          "version": "6.4.0",
+        "punycode": {
+          "version": "1.4.1",
           "bundled": true,
           "dev": true,
           "optional": true
@@ -2142,6 +2183,7 @@
           "version": "2.2.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "buffer-shims": "1.0.0",
             "core-util-is": "1.0.2",
@@ -2186,6 +2228,7 @@
           "version": "2.6.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "glob": "7.1.2"
           }
@@ -2193,7 +2236,8 @@
         "safe-buffer": {
           "version": "5.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "semver": {
           "version": "5.3.0",
@@ -2247,24 +2291,26 @@
             }
           }
         },
-        "string_decoder": {
-          "version": "1.0.1",
-          "bundled": true,
-          "dev": true,
-          "requires": {
-            "safe-buffer": "5.0.1"
-          }
-        },
         "string-width": {
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "1.1.0",
             "is-fullwidth-code-point": "1.0.0",
             "strip-ansi": "3.0.1"
           }
         },
+        "string_decoder": {
+          "version": "1.0.1",
+          "bundled": true,
+          "dev": true,
+          "optional": true,
+          "requires": {
+            "safe-buffer": "5.0.1"
+          }
+        },
         "stringstream": {
           "version": "0.0.5",
           "bundled": true,
@@ -2275,6 +2321,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "2.1.1"
           }
@@ -2289,6 +2336,7 @@
           "version": "2.2.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "block-stream": "0.0.9",
             "fstream": "1.0.11",
@@ -2344,7 +2392,8 @@
         "util-deprecate": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "uuid": {
           "version": "3.0.1",
@@ -2373,7 +2422,8 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -3275,10 +3325,11 @@
       "dev": true
     },
     "qs": {
-      "version": "6.5.1",
-      "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
-      "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A==",
-      "dev": true
+      "version": "6.4.0",
+      "resolved": "https://registry.npmjs.org/qs/-/qs-6.4.0.tgz",
+      "integrity": "sha512-Qs6dfgR5OksK/PSxl1kGxiZgEQe8RqJMB9wZqVlKQfU+zzV+HY77pWJnoJENACKDQByWdpr8ZPIh1TBi4lpiSQ==",
+      "dev": true,
+      "optional": true
     },
     "querystring": {
       "version": "0.2.0",