Merge pull request #9 from IndigoUnited/greenkeeper/chai-4.0.0

Update chai to the latest version 🚀

Author: satazor

package.json

@@ -33,7 +33,7 @@
   "devDependencies": {
     "@satazor/eslint-config": "^3.0.0",
     "browserify": "^14.0.0",
-    "chai": "^3.4.1",
+    "chai": "^4.0.0",
     "coveralls": "^2.11.6",
     "eslint": "^3.0.0",
     "istanbul": "^0.4.1",