build(deps-dev): bump invoke from 1.5.0 to 1.6.0 (#5)

Bumps [invoke](https://github.com/bitprophet/alabaster) from 1.5.0 to 1.6.0.
- [Release notes](https://github.com/bitprophet/alabaster/releases)
- [Changelog](https://github.com/bitprophet/alabaster/blob/master/docs/changelog.rst)
- [Commits](https://github.com/bitprophet/alabaster/commits)

---
updated-dependencies:
- dependency-name: invoke
  dependency-type: direct:development
  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>

requirements_dev.txt

@@ -6,7 +6,7 @@ coverage==5.5
 black==21.6b0
 commitizen==2.17.12
 flake8==3.9.2
-invoke==1.5.0
+invoke==1.6.0
 isort==5.9.2
 mypy==0.910
 pre-commit==2.13.0