Add GitHub workflow files for CI/CD

[EndlessTrax]

Adds four files:

1. Lint workflow file that is triggered on every push + pr to master
2. Test workflow file that is triggered on every push + pr to master
3. Release workflow file that is triggered on every tag that matches a semvar release
4. A dependabot config file for automating prs for requirement updates and security patches.

[EndlessTrax]

@bzaczynski Great. I'll get writing the tutorial before we merge, just in case there's any last-minute tweaks.