Bump react-dom from 16.2.0 to 16.2.1 in /frontend

Bumps [react-dom](https://github.com/facebook/react/tree/HEAD/packages/react-dom) from 16.2.0 to 16.2.1.
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/master/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/HEAD/packages/react-dom)

Signed-off-by: dependabot[bot] <support@github.com>

frontend/package.json

@@ -36,7 +36,7 @@
     "raven-js": "^3.22.0",
     "react": "^16.0.0",
     "react-burger-menu": "^2.2.3",
-    "react-dom": "^16.2.0",
+    "react-dom": "^16.2.1",
     "react-ga": "^2.4.1",
     "react-redux": "^5.0.6",
     "react-router-dom": "^4.2.2",

frontend/yarn.lock

@@ -5500,9 +5500,9 @@ react-deep-force-update@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/react-deep-force-update/-/react-deep-force-update-1.1.1.tgz#bcd31478027b64b3339f108921ab520b4313dc2c"
 
-react-dom@^16.2.0:
-  version "16.2.0"
-  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-16.2.0.tgz#69003178601c0ca19b709b33a83369fe6124c044"
+react-dom@^16.2.1:
+  version "16.2.1"
+  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-16.2.1.tgz#5cfb32f66267ece7b3850466bf3b219d4911fc1a"
   dependencies:
     fbjs "^0.8.16"
     loose-envify "^1.1.0"