chore(package): update http-server to version 0.12.3

Closes #2

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
   "devDependencies": {
     "cssnano": "^3.9.1",
     "del-cli": "^0.2.1",
-    "http-server": "^0.9.0",
+    "http-server": "^0.12.3",
     "npmpub": "^3.1.0",
     "postcss-cli": "^2.6.0",
     "postcss-cssnext": "^2.9.0",