chore(package): update mocha to version 6.1.3

Closes #8

Author: greenkeeper[bot]

package.json

@@ -46,6 +46,6 @@
     "iced-coffee-coverage": "^1.0.3",
     "iced-coffee-script": "^108.0.11",
     "istanbul": "^0.4.5",
-    "mocha": "^3.0.2"
+    "mocha": "^6.1.3"
   }
 }