ENH: Add release manager

[kaitj]

Proposed changes

This PR adds in automatic version management using release-drafter, where release notes are automatically drafted / updated from PR titles (so please make sure these are meaningful moving forward) and performs version bumping as necessary. This largely follows semantic versioning, but is based off of the labels assigned to a PR. As such, the labels are also important:

• skip_changelog - will ignore the PR in the drafted release notes
• breaking - will trigger a major release bump
• enhancement will trigger a minor release bump
• bug, maintenance, and dependency will trigger patch bumps

If none of these are specified, it will default to a patch bump.

Will note that this currently has no way of updating any files within the repository and am looking into a way of possibly grabbing the version from the latest published release and updating a package.json file or such.
As of 34452ab, a version has been added to setup.py and has been tested to work on a forked branch. This version only gets bumped if a deployment to heroku happens (similar to publishing the release notes). It uses gha-find-replace to find the version in setup.py via regex, and replaces it using the tag from release-drafter. This is all done local to the action, so the github-actions bot credentials are used to commit the changes as part of the workflow and pushes it back the master branch.

Note: This is currently failing the github actions, but taking a look at it, it seems like this error is happening because there is no corresponding YAML file in the default branch

Types of changes

What types of changes does your code introduce? Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionalitiy)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you are unsure about any of the choices, don't hesitate to ask!

• Changes have been tested to ensure that fix is effective or that a feature works.
• Changes pass the unit tests
• Code has been run through black with the -l 79 flag.
• I have included necessary documentation or comments (as necessary)
• Any dependent changes have been merged and published

Notes

All PRs will undergo the unit testing before being reviewed. You may be requested to explain or make additional changes before the PR is accepted.

PR template was adopted from appium

[tkkuehn]

Looks good to me!