Enable function expressions (#393)

* Bump js-slang

* Update yarn.lock

package.json

@@ -37,7 +37,7 @@
  "draft-js": "^0.10.5",
  "flexboxgrid": "^6.3.1",
  "flexboxgrid-helpers": "^1.1.3",
- "js-slang": "0.1.13",
+ "js-slang": "0.1.14",
  "lodash": "^4.17.10",
  "lz-string": "^1.4.4",
  "moment": "^2.22.2",

yarn.lock

@@ -5926,10 +5926,10 @@ js-base64@^2.1.9:
  resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.4.3.tgz#2e545ec2b0f2957f41356510205214e98fad6582"
  integrity sha512-H7ErYLM34CvDMto3GbD6xD0JLUGYXR3QTcH6B/tr4Hi/QpSThnCsIp+Sy5FRTw3B0d6py4HcNkW7nO/wdtGWEw==
 
-[email protected].13:
- version "0.1.13"
- resolved "https://registry.yarnpkg.com/js-slang/-/js-slang-0.1.13.tgz#bee31777b967d02eefac09226ca78bf12d6f19a1"
- integrity sha512-oD05dO+lxf+ovkRNPHk2kaudF1GloM7ENqNmTA1tbWIfD1RfpLTdDmrkZahqZwtAJf3PvK0Ijst57zkeNrlojQ==
+[email protected].14:
+ version "0.1.14"
+ resolved "https://registry.yarnpkg.com/js-slang/-/js-slang-0.1.14.tgz#7df10d980bbd0f65e4ee6813d26db5b544d64ce2"
+ integrity sha512-j2zLfhRrDN0uSJrR9N1nFMQ4nOqiFrSLOa+hqbuPbcUsMlSV9hDYy9tZ/ZyW1oB2gpRyzCFvJRvkEkde7ooBlQ==
  dependencies:
  "@types/acorn" "^4.0.3"
  "@types/estree" "0.0.39"