Bump superagent from 2.3.0 to 5.0.2

Bumps [superagent](https://github.com/visionmedia/superagent) from 2.3.0 to 5.0.2.
- [Release notes](https://github.com/visionmedia/superagent/releases)
- [Changelog](https://github.com/visionmedia/superagent/blob/master/HISTORY.md)
- [Commits](ladjs/superagent@v2.3.0...v5.0.2)

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

Author: dependabot[bot]

package-lock.json

@@ -85,7 +85,7 @@
     "react-tap-event-plugin": "^1.0.0",
     "redux": "^3.5.2",
     "redux-saga": "^0.13.0",
-    "superagent": "^2.1.0",
+    "superagent": "^5.0.2",
     "superagent-intercept": "^0.1.1",
     "validator": "^5.7.0"
   },