fix(util): correctly clean up duplicate slashes, fixed #153

Author: QingWei-Li

src/core/route/util.js

@@ -54,5 +54,5 @@ export const getParentPath = cached(path => {
 })
 
 export const cleanPath = cached(path => {
-  return path.replace(/\/+/g, '/')
+  return path.replace(/([^:])\/{2,}/g, '$1/')
 })