Bump got and tslint in /openhtf/output/web_gui

Removes [got](https://github.com/sindresorhus/got). It's no longer used after updating ancestor dependency [tslint](https://github.com/palantir/tslint). These dependencies need to be updated together.


Removes `got`

Updates `tslint` from 4.5.1 to 5.20.1
- [Release notes](https://github.com/palantir/tslint/releases)
- [Changelog](https://github.com/palantir/tslint/blob/master/CHANGELOG.md)
- [Commits](palantir/tslint@4.5.1...5.20.1)

---
updated-dependencies:
- dependency-name: got
  dependency-type: indirect
- dependency-name: tslint
  dependency-type: direct:development
...

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