/**
  * Update the specified resource in storage.
  *
  * @param  int  $id
  * @return Response
  */
 public function update($id, UpdatePermissionRequest $request)
 {
     $name = $request->get('name');
     $readableName = $request->get('readable_name');
     $count = Permission::whereName($name)->where('id', '!=', $id)->count();
     if ($count > 0) {
         return $this->redirectWithError('路由名称不能重复');
     }
     $count = Permission::whereEmail($readableName)->where('id', '!=', $id)->count();
     if ($count > 0) {
         return $this->redirectWithError('权限显示名称不能重复');
     }
     $data = ['name' => $name, 'readable_name' => $readableName];
     Permission::findOrFail($id)->update($data);
     return redirect()->route('admin.permissions.index');
 }