Bump core-js from 2.6.5 to 3.9.0

Bumps [core-js](https://github.com/zloirock/core-js) from 2.6.5 to 3.9.0.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](zloirock/core-js@v2.6.5...v3.9.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

package.json

@@ -55,7 +55,7 @@
     "babel-loader": "8.0.5",
     "babel-plugin-transform-rename-import": "2.3.0",
     "bootstrap-sass": "3.4.1",
-    "core-js": "2.6.5",
+    "core-js": "3.9.0",
     "cross-env": "5.2.0",
     "css-loader": "2.1.1",
     "enzyme": "3.9.0",

yarn.lock

@@ -3411,26 +3411,22 @@ [email protected]:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/core-js-pure/-/core-js-pure-3.0.1.tgz#37358fb0d024e6b86d443d794f4e37e949098cbe"
 
-[email protected], core-js@^2.4.0, core-js@^2.5.7:
-  version "2.6.5"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.5.tgz#44bc8d249e7fb2ff5d00e0341a7ffb94fbf67895"
-
 [email protected]:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.0.1.tgz#1343182634298f7f38622f95e73f54e48ddf4738"
 
+[email protected], core-js@^3.0.0:
+  version "3.9.0"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.9.0.tgz#790b1bb11553a2272b36e2625c7179db345492f8"
+
 core-js@^1.0.0:
   version "1.2.7"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-1.2.7.tgz#652294c14651db28fa93bd2d5ff2983a4f08c636"
 
-core-js@^2.6.5:
+core-js@^2.4.0, core-js@^2.5.7, core-js@^2.6.5:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.9.tgz#6b4b214620c834152e179323727fc19741b084f2"
 
-core-js@^3.0.0:
-  version "3.1.4"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.1.4.tgz#3a2837fc48e582e1ae25907afcd6cf03b0cc7a07"
-
 [email protected], core-util-is@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"