chore(package): update postcss-at-rules-variables to version 0.0.25

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -44,7 +44,7 @@
     "gulp-gh-pages": "^0.5.4",
     "gulp-postcss": "^6.1.1",
     "gulp-rename": "^1.2.2",
-    "postcss-at-rules-variables": "0.0.24",
+    "postcss-at-rules-variables": "0.0.25",
     "postcss-attribute-selector-prefix": "0.0.9",
     "postcss-banner": "^3.0.0",
     "postcss-browser-reporter": "^0.5.0",