Upgrade core-js

This package is used by webpack.

package-lock.json

@@ -3071,9 +3071,9 @@
       "integrity": "sha1-Z29us8OZl8LuGsOpJP1hJHSPV40="
     },
     "core-js": {
-      "version": "3.1.4",
-      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.1.4.tgz",
-      "integrity": "sha512-YNZN8lt82XIMLnLirj9MhKDFZHalwzzrL9YLt6eb0T5D0EDl4IQ90IGkua8mHbnxNrkj1d8hbdizMc0Qmg1WnQ=="
+      "version": "3.6.4",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.6.4.tgz",
+      "integrity": "sha512-4paDGScNgZP2IXXilaffL9X7968RuvwlkK3xWtZRVqgd8SYNiVKRJvkFd1aqqEuPfN7E68ZHEp9hDj6lHj4Hyw=="
     },
     "core-js-compat": {
       "version": "3.6.4",

package.json

@@ -64,7 +64,7 @@
     "angularjs-scroll-glue": "=2.1.0",
     "autolinker": "^3.12.0",
     "babel-loader": "^8.0.6",
-    "core-js": "^3.1.4",
+    "core-js": "^3.6.4",
     "croppie": "^2.6.4",
     "emojibase-regex": "^3.2.0",
     "file-saver": "^2.0.2",