chore(package): update autoprefixer to version 8.3.0

Author: greenkeeper[bot]

package.json

@@ -49,7 +49,7 @@
     "@types/node": "9.6.5",
     "angular-cli-ghpages": "0.5.2",
     "angular2-template-loader": "0.6.2",
-    "autoprefixer": "8.2.0",
+    "autoprefixer": "8.3.0",
     "awesome-typescript-loader": "3.3.0",
     "codelyzer": "4.0.0",
     "commitplease": "3.2.0",