Merge pull request #259 from jupyterhub/dependabot/npm_and_yarn/commander-6.1.0

Bump commander from 5.1.0 to 6.1.0

Author: consideRatio

package-lock.json

@@ -9,7 +9,7 @@
     "url": "https://github.com/jupyterhub/configurable-http-proxy.git"
   },
   "dependencies": {
-    "commander": "~5.1.0",
+    "commander": "~6.1.0",
     "http-proxy": "^1.18.1",
     "lynx": "^0.2.0",
     "strftime": "~0.10.0",