Add rtlcss package

Author: sidati

package.json

@@ -19,7 +19,8 @@
     "postcss-modules-local-by-default": "^1.0.1",
     "postcss-modules-scope": "^1.0.0",
     "postcss-modules-values": "^1.1.0",
-    "source-list-map": "^0.1.7"
+    "source-list-map": "^0.1.7",
+    "rtlcss": "^2.0.2"
   },
   "devDependencies": {
     "codecov.io": "^0.1.2",