chore(package): update chai to version 4.1.2

Closes #37

Author: greenkeeper[bot]

package.json

@@ -68,7 +68,7 @@
     "babel-eslint": "7.1.0",
     "babel-preset-react-hmre": "^1.1.1",
     "babel-standalone": "^6.7.7",
-    "chai": "~3.5.0",
+    "chai": "~4.1.2",
     "css-modules-require-hook": "~4.0.5",
     "eslint": "3.9.1",
     "eslint-plugin-react": "6.6.0",