Bump greenlet from 0.4.17 to 2.0.1

Bumps [greenlet](https://github.com/python-greenlet/greenlet) from 0.4.17 to 2.0.1.
- [Release notes](https://github.com/python-greenlet/greenlet/releases)
- [Changelog](https://github.com/python-greenlet/greenlet/blob/master/CHANGES.rst)
- [Commits](python-greenlet/greenlet@0.4.17...2.0.1)

---
updated-dependencies:
- dependency-name: greenlet
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -26,7 +26,7 @@ gevent==20.9.0
 GeoAlchemy2==0.8.4
 geojson==1.3.4
 glob2==0.7
-greenlet==0.4.17
+greenlet==2.0.1
 gunicorn==20.0.4
 idna==2.10
 itsdangerous==1.1.0