update postcss to 7.x, postcss-selector-parser to 5.x

Author: nelsonpecora

lib/style-rewriter.js

@@ -24,7 +24,7 @@ var addId = postcss.plugin('add-id', function () {
             attribute: currentId
           }))
         })
-      }).process(node.selector).result
+      }).processSync(node)
     })
   }
 })
@@ -81,4 +81,3 @@ module.exports = function (id, css, scoped, options) {
       })
   }
 }
-