diff --git a/Gemfile.lock b/Gemfile.lock
index 452882b..6ba818e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -19,30 +19,20 @@ GEM
       rake
       thor (>= 0.14.0)
     ast (2.4.2)
-    colorize (0.7.5)
     concurrent-ruby (1.2.2)
-    coveralls (0.5.8)
-      colorize
-      json
-      rest-client
-      simplecov (>= 0.7)
-      thor
+    coveralls (0.8.23)
+      json (>= 1.8, < 3)
+      simplecov (~> 0.16.1)
+      term-ansicolor (~> 1.3)
+      thor (>= 0.19.4, < 2.0)
+      tins (~> 1.6)
     diff-lcs (1.2.5)
-    docile (1.1.5)
-    domain_name (0.5.20190701)
-      unf (>= 0.0.5, < 1.0.0)
-    http-cookie (1.0.3)
-      domain_name (~> 0.5)
+    docile (1.4.0)
     i18n (1.12.0)
       concurrent-ruby (~> 1.0)
-    json (2.3.1)
-    mime-types (3.2.2)
-      mime-types-data (~> 3.2015)
-    mime-types-data (3.2019.0331)
+    json (2.7.1)
     mini_portile2 (2.8.5)
     minitest (5.14.4)
-    multi_json (1.1.0)
-    netrc (0.11.0)
     parallel (1.24.0)
     parser (3.3.0.4)
       ast (~> 2.4.1)
@@ -51,10 +41,6 @@ GEM
     rainbow (3.1.1)
     rake (13.0.1)
     regexp_parser (2.9.0)
-    rest-client (2.0.2)
-      http-cookie (>= 1.0.2, < 2.0)
-      mime-types (>= 1.16, < 4.0)
-      netrc (~> 0.8)
     rexml (3.2.6)
     rspec (3.5.0)
       rspec-core (~> 3.5.0)
@@ -91,19 +77,21 @@ GEM
       rubocop (>= 0.90.0, < 2.0)
       rubocop-ast (>= 0.4.0)
     ruby-progressbar (1.13.0)
-    simplecov (0.9.2)
-      docile (~> 1.1.0)
-      multi_json (~> 1.0)
-      simplecov-html (~> 0.9.0)
-    simplecov-html (0.9.0)
+    simplecov (0.16.1)
+      docile (~> 1.1)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.2)
     sqlite3 (1.7.0)
       mini_portile2 (~> 2.8.0)
-    thor (0.19.1)
+    sync (0.5.0)
+    term-ansicolor (1.7.1)
+      tins (~> 1.0)
+    thor (1.3.0)
+    tins (1.32.1)
+      sync
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unf (0.1.4)
-      unf_ext
-    unf_ext (0.0.7.6)
     unicode-display_width (2.5.0)
 
 PLATFORMS