chore(package): update gulp-mocha to version 7.0.2

Closes #89

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "del": "5.0.0",
     "gulp": "4.0.2",
     "gulp-istanbul": "1.1.3",
-    "gulp-mocha": "6.0.0",
+    "gulp-mocha": "7.0.2",
     "gulp-sourcemaps": "2.6.x",
     "gulp-tslint": "8.1.4",
     "gulp-typescript": "5.0.1",