Update postcss-scss to version 2.0.0 (#370)

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
     "eslint-plugin-import": "^2.2.0",
     "eslint-plugin-prettier": "^2.2.0",
     "npmpub": "^4.0.0",
-    "postcss-scss": "^1.0.0",
+    "postcss-scss": "^2.0.0",
     "prettier": "1.14.0",
     "sugarss": "^1.0.0"
   },