Bump PostCSS version

Author: timdorr

package.json

@@ -35,7 +35,7 @@
   "homepage": "https://github.com/geelen/postcss-modules-scope",
   "dependencies": {
     "css-selector-tokenizer": "^0.5.0",
-    "postcss": "^4.1.11"
+    "postcss": "^5.0.4"
   },
   "devDependencies": {
     "babel": "^5.4.7",