Upgrade webpack and core-js

package.json

@@ -44,7 +44,7 @@
     "classnames": "2.2.6",
     "clipboard": "2.0.6",
     "connected-react-router": "6.8.0",
-    "core-js": "3",
+    "core-js": "3.6.5",
     "create-react-class": "15.6.3",
     "css-loader": "3.0.0",
     "del": "5.0.0",
@@ -122,7 +122,7 @@
     "stylelint": "10.1.0",
     "stylelint-order": "3.0.1",
     "url-loader": "2.0.1",
-    "webpack": "4.35.3",
+    "webpack": "4.44.2",
     "webpack-stream": "5.2.1",
     "worker-loader": "2.0.0"
   },