Update dependencies, add npm lockfile

Author: eemeli

package-lock.json

@@ -26,7 +26,7 @@
   ],
   "devDependencies": {
     "expect.js": "^0.3.1",
-    "mocha": "^3.0.2",
+    "mocha": "^4.0.1",
     "pegjs": "^0.10.0"
   },
   "scripts": {