Bump superagent from 0.12.4 to 9.0.0

Bumps [superagent](https://github.com/ladjs/superagent) from 0.12.4 to 9.0.0.
- [Release notes](https://github.com/ladjs/superagent/releases)
- [Changelog](https://github.com/ladjs/superagent/blob/master/HISTORY.md)
- [Commits](ladjs/superagent@0.12.4...v9.0.0)

---
updated-dependencies:
- dependency-name: superagent
  dependency-type: direct:development
...

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

package.json

@@ -34,7 +34,7 @@
     "grunt-simple-mocha": "0.4.x",
     "mocha": "^1.17.1",
     "restify": "2.x",
-    "superagent": "0.12.x"
+    "superagent": "9.0.x"
   },
   "keywords": [
     "hmac",