Fixed lint error on CI (vuejs#1008)

Author: ota-meshi

package.json

@@ -56,8 +56,9 @@
  "chai": "^4.1.0",
  "eslint": "^6.0.0",
  "eslint-plugin-eslint-plugin": "^2.0.1",
- "eslint-plugin-vue-libs": "^4.0.0",
+ "eslint-plugin-import": "^2.18.2",
  "eslint-plugin-vue": "file:.",
+ "eslint-plugin-vue-libs": "^4.0.0",
  "eslint4b": "^6.6.0",
  "lodash": "^4.17.4",
  "mocha": "^5.2.0",