Update package.json

* Updated: corejs to version 3.x.x

Author: smwbtech

package.json

@@ -59,7 +59,7 @@
 "babel-plugin-transform-vue-jsx": "^3.7.0",
 "babel-preset-env": "^1.7.0",
 "babel-preset-minify": "^0.5.1",
-"core-js": "^2.6.5",
+"core-js": "^3.6.4",
 "coveralls": "^3.0.6",
 "cross-env": "^5.2.0",
 "eslint": "^5.16.0",