Bump uvicorn from 0.20.0 to 0.21.0 (#81)

Bumps [uvicorn](https://github.com/encode/uvicorn) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/encode/uvicorn/releases)
- [Changelog](https://github.com/encode/uvicorn/blob/master/CHANGELOG.md)
- [Commits](encode/uvicorn@0.20.0...0.21.0)

---
updated-dependencies:
- dependency-name: uvicorn
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,4 +1,4 @@
 fastapi==0.93.0
 aiohttp==3.8.4
 aiocache==0.12.0
-uvicorn==0.20.0
+uvicorn==0.21.0