build(mocha): Bumped to mocha 6

Author: grantila

package.json

@@ -41,7 +41,7 @@
     "commitizen": "3.x",
     "cz-conventional-changelog": "2.x",
     "jsdom": "11.x",
-    "mocha": "5.x",
+    "mocha": "6.x",
     "pre-commit": "1.x",
     "rimraf": "2.x",
     "semantic-release": "15.x",