chore(package): update autoprefixer to version 9.8.0

Closes #63

Author: greenkeeper[bot]

package.json

@@ -53,7 +53,7 @@
     "angular-cli-ghpages": "0.5.3",
     "angular2-template-loader": "0.6.2",
     "ansi-colors": "3.2.4",
-    "autoprefixer": "9.5.0",
+    "autoprefixer": "9.8.0",
     "awesome-typescript-loader": "5.2.1",
     "codelyzer": "4.5.0",
     "commitplease": "3.2.0",