chore(deps-dev): bump black from 21.6b0 to 21.7b0

Bumps [black](https://github.com/psf/black) from 21.6b0 to 21.7b0.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](https://github.com/psf/black/commits)

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

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

Author: dependabot[bot]

poetry.lock

@@ -63,7 +63,7 @@ codecov = "*"
 coverage = "*"
 
 ### Format ###
-black = {version="==21.6b0", python="^3.6.2"}
+black = {version="==21.7b0", python="^3.6.2"}
 isort = "*"
 
 ### Lint ###