chore(package): update mocha to version 7.2.0

Closes #37

Author: greenkeeper[bot]

package.json

@@ -48,7 +48,7 @@
     "eslint-config-airbnb-base": "^12.1.0",
     "eslint-plugin-import": "^2.8.0",
     "in-publish": "^2.0.0",
-    "mocha": "^4.0.1",
+    "mocha": "^7.2.0",
     "react": "~15.4",
     "react-dom": "~15.4",
     "react-native": "^0.42.0",