feat!: update the base config to v14, supports eslint 6 and drops eslint v4 support

Author: haoqunjiang

package.json

@@ -21,12 +21,12 @@
   },
   "homepage": "https://github.com/vuejs/eslint-config-airbnb#readme",
   "dependencies": {
-    "eslint-config-airbnb-base": "^13.1.0",
+    "eslint-config-airbnb-base": "^14.0.0",
     "eslint-import-resolver-webpack": "^0.11.1",
-    "eslint-plugin-import": "^2.17.3"
+    "eslint-plugin-import": "^2.18.2"
   },
   "peerDependencies": {
-    "eslint": "^4.19.1 || ^5.3.0",
+    "eslint": "^5.16.0 || ^6.1.0",
     "@vue/cli-service": "^3.0.0 || ^4.0.0-0"
   }
 }