Avoid redundant global self-require of the plugin (#1317)

* Avoid redundant global require

* Bring back alias to self

Author: constgen

lib/rules/no-unregistered-components.js

@@ -8,8 +8,8 @@
 // Requirements
 // ------------------------------------------------------------------------------
 
-const utils = require('eslint-plugin-vue/lib/utils')
-const casing = require('eslint-plugin-vue/lib/utils/casing')
+const utils = require('../utils')
+const casing = require('../utils/casing')
 
 // ------------------------------------------------------------------------------
 // Rule helpers