fix stylus path (#14)

closes #11

Author: andrewharvey

generator/templates/default/src/plugins/vuetify.js

@@ -12,7 +12,7 @@ import {
   VToolbar,
   transitions
 } from 'vuetify'
-import '../node_modules/vuetify/src/stylus/app.styl'
+import 'vuetify/src/stylus/app.styl'
 <%_ } else { _%>
 import Vuetify from 'vuetify'
 import 'vuetify/dist/vuetify.min.css'
@@ -43,4 +43,4 @@ Vue.use(Vuetify, {
     warning: '#FFC107'
   },
 <%_ } _%>
-})
+})