chore: remove commander

Author: arek czogala

package-lock.json

@@ -33,7 +33,6 @@
   ],
   "homepage": "https://github.com/makeros/gelf-transformer#readme",
   "dependencies": {
-    "commander": "^3.0.1",
     "fast-json-parse": "^1.0.3",
     "fast-json-stringify": "^2.4.2",
     "lodash.get": "^4.4.2",