Treat Vue.mixin as components

Author: armano2

lib/utils/index.js

@@ -370,7 +370,7 @@ module.exports = {
       callee.object.type === 'Identifier' &&
       callee.object.name === 'Vue' &&
       callee.property.type === 'Identifier' &&
-      callee.property.name === 'component' &&
+      (callee.property.name === 'component' || callee.property.name === 'mixin') &&
       node.arguments.length &&
       node.arguments.slice(-1)[0].type === 'ObjectExpression'