fix(package): update autoprefixer to version 8.5.0

Closes #339

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
   "author": "Satyajit Sahoo <[email protected]> (https://github.com/satya164/)",
   "license": "MIT",
   "dependencies": {
-    "autoprefixer": "^7.1.6",
+    "autoprefixer": "^8.5.0",
     "babel-core": "^6.26.0",
     "babel-loader": "^7.1.2",
     "babel-plugin-transform-react-constant-elements": "^6.23.0",