chore: Upgrade package dependencies

BREAKING CHANGE: Dependencies (commander, at least) dropped support for Node.js 4. Node.js 6 should still work, but officially it is not supported either. You should upgrade to the current or still supported Node.js LTS version.

Author: prantlf

package-lock.json

@@ -64,14 +64,14 @@
   ],
   "dependencies": {
     "ajv": "6.10.2",
-    "commander": "3.0.1"
+    "commander": "4.0.1"
   },
   "devDependencies": {
-    "http-server": "0.11.1",
+    "http-server": "0.12.0",
     "js-yaml": "3.13.1",
     "nyc": "14.1.1",
     "standard": "14.3.1",
     "test": "0.6.0",
-    "uglify-js": "3.6.0"
+    "uglify-js": "3.7.2"
   }
 }