[pkg] Update mocha to version 7.2.0 (#127)

package.json

@@ -25,7 +25,7 @@
     "node-gyp-build": "~4.2.0"
   },
   "devDependencies": {
-    "mocha": "~7.1.0",
+    "mocha": "~7.2.0",
     "prebuildify": "~4.0.0"
   }
 }