Bump monty from 2021.7.8 to 2021.8.17

Bumps [monty](https://github.com/materialsvirtuallab/monty) from 2021.7.8 to 2021.8.17.
- [Release notes](https://github.com/materialsvirtuallab/monty/releases)
- [Changelog](https://github.com/materialsvirtuallab/monty/blob/master/docs/changelog.html)
- [Commits](materialsvirtuallab/monty@v2021.7.8...v2021.8.17)

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

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

requirements.txt

@@ -3,6 +3,6 @@ pymatgen==2022.0.11
 typing-extensions==3.10.0.0
 maggma==0.31.0
 requests==2.26.0
-monty==2021.7.8
+monty==2021.8.17
 emmet-core==0.10.0
 ratelimit==2.2.1