build: update eslint

package.json

@@ -54,8 +54,8 @@
     "cross-env": "^5.2.0",
     "cross-spawn": "^6.0.5",
     "css-loader": "^2.1.0",
-    "eslint": "^5.12.0",
-    "eslint-plugin-vue-libs": "^3.0.0",
+    "eslint": "^6.8.0",
+    "eslint-plugin-vue-libs": "^4.0.0",
     "express": "^4.14.1",
     "jasmine": "2.8.0",
     "jasmine-core": "2.8.0",