Add selector AST parser

Author: dqbd

package.json

@@ -16,12 +16,14 @@
   "dependencies": {
     "escape-string-regexp": "^1.0.3",
     "extend": "^3.0.1",
-    "postcss": "^6.0.8"
+    "postcss": "^6.0.8",
+    "postcss-selector-parser": "^6.0.2"
   },
   "devDependencies": {
     "bluebird": "^3.5.0",
     "chai": "^4.1.1",
     "chai-as-promised": "^7.1.1",
+    "chalk": "^2.4.2",
     "cssnano": "^4.0.0",
     "eslint": "^4.4.1",
     "eslint-plugin-react": "^7.1.0",