Fix path

Author: adamwathan

__tests__/util/invokePlugin.js

@@ -1,5 +1,5 @@
 import _ from 'lodash'
-import escapeClassName from '../../../src/util/escapeClassName'
+import escapeClassName from '../../src/util/escapeClassName'
 
 export default function(plugin, config) {
   const addedUtilities = []