Bump http-proxy from 1.16.2 to 1.18.1

Bumps [http-proxy](https://github.com/http-party/node-http-proxy) from 1.16.2 to 1.18.1.
- [Release notes](https://github.com/http-party/node-http-proxy/releases)
- [Changelog](https://github.com/http-party/node-http-proxy/blob/master/CHANGELOG.md)
- [Commits](http-party/node-http-proxy@1.16.2...1.18.1)

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

Author: dependabot[bot]

package-lock.json

@@ -123,7 +123,7 @@
     "file-loader": "^4.2.0",
     "happypack": "^5.0.0",
     "html-webpack-plugin": "^3.2.0",
-    "http-proxy": "~1.16.2",
+    "http-proxy": "~1.18.1",
     "jest": "^23.6.0",
     "jsdom": "^12.2.0",
     "less": "~2.7.1",