Merge pull request #1475 from mozilla/greenkeeper/postcss-loader-1.2.1

Update postcss-loader to the latest version 🚀

package.json

@@ -236,7 +236,7 @@
     "mocha": "3.2.0",
     "node-sass": "3.13.1",
     "po2json": "0.4.5",
-    "postcss-loader": "1.2.0",
+    "postcss-loader": "1.2.1",
     "react-addons-test-utils": "15.3.2",
     "react-hot-loader": "1.3.0",
     "react-transform-hmr": "1.0.4",