chore(package): update mocha to version 7.2.0

Closes #35

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
     "babel-preset-es2015": "^6.24.1",
     "babel-register": "^6.26.0",
     "chai": "^4.2.0",
-    "mocha": "^6.1.4",
+    "mocha": "^7.2.0",
     "pre-commit": "^1.2.2",
     "standard": "^12.0.1"
   },