chore(package): update mocha to version 7.0.1

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "yeoman-generator": "^4.0.1"
   },
   "devDependencies": {
-    "mocha": "^6.1.4",
+    "mocha": "^7.0.1",
     "xo": "^0.25.3",
     "yeoman-assert": "^3.1.1",
     "yeoman-test": "^2.0.0"