Merge pull request #96 from litixsoft/greenkeeper-chai-4.0.0

Update chai to version 4.0.0 🚀

Author: 4kochi

package.json

@@ -54,7 +54,7 @@
         "demo": "grunt demo --force"
     },
     "devDependencies": {
-        "chai": "^3.5.0",
+        "chai": "^4.0.0",
         "grunt": "^1.0.1",
         "grunt-bump": "^0.8.0",
         "grunt-contrib-copy": "^1.0.0",