chore(package): update postcss-cli to version 5.0.0

Author: greenkeeper[bot]

package.json

@@ -62,7 +62,7 @@
     "nsp": "^3.0.0",
     "nyc": "^11.3.0",
     "postcss-at-rules-variables": "^0.1.1",
-    "postcss-cli": "^4.1.0",
+    "postcss-cli": "^5.0.0",
     "postcss-custom-properties": "^6.1.0",
     "postcss-discard-comments": "^4.0.0-rc.2",
     "postcss-each": "^0.10.0",