Template CRUD

[jbothma]

should be deployable without the migration and minio config, but these endpoints won't work til this is in the environment OpenUpSA/agari-helm#11

• Adds test_health.py, github actions workflow for CI, and docker-compose file for local test runs
• Adds endpoints to CRUD templates
  • files are uploaded to minio
  • metadata is stored in folio db
• Moves env var lookups to settings.py to make them more discoverable and ease overriding them for tests
• Adds a migration for the new db table and related bits