feat(package): upgrade autoprefixer to 9.1.3

Author: joshuawilson

package.json

@@ -112,7 +112,7 @@
     "angular2-router-loader": "0.3.5",
     "angular2-template-loader": "0.6.2",
     "assets-webpack-plugin": "3.9.6",
-    "autoprefixer": "9.1.0",
+    "autoprefixer": "9.1.3",
     "child_process": "1.0.2",
     "clean-css": "4.2.0",
     "clean-webpack-plugin": "0.1.19",