0.6.0

• Add docs about installing and pinning dependencies. PR #19.
• Add slim version. PR #18.
• Fix testing race condition by sending the request first PR #17.
• Update and refactor bringing all the new features from the base image. Includes:
  • Centralize, simplify, and deduplicate code and setup
  • Move CI to GitHub actions
  • Add Python 3.8 (and Alpine)
  • Add new configs and docs:
    • WORKER_CLASS
    • TIMEOUT
    • KEEP_ALIVE
    • GRACEFUL_TIMEOUT
    • ACCESS_LOG
    • ERROR_LOG
    • GUNICORN_CMD_ARGS
    • MAX_WORKERS
  • PR #16.
• Disable pip cache during installation. PR #15.
• Migrate local development from Pipenv to Poetry. PR #14.
• Add docs for custom PRE_START_PATH env var. PR #13.