Merge pull request #945 from graphql/greenkeeper/chai-4.1.0

Update chai to the latest version 🚀

Author: wincent

package.json

@@ -48,7 +48,7 @@
     "babel-plugin-transform-flow-strip-types": "6.22.0",
     "babel-plugin-transform-object-rest-spread": "6.23.0",
     "babel-preset-env": "^1.5.2",
-    "chai": "4.0.2",
+    "chai": "4.1.0",
     "chai-json-equal": "0.0.1",
     "chai-spies-next": "^0.8.0",
     "chai-subset": "1.5.0",