Create local dev docker-compose.yml that uses filesystem instead of minio for testing different infrastructures

[cjcolvar]

Avalon can be configured to work in many different infrastructure environments. The most common are AWS, docker-compose, and capistrano/bare metal. Each of these uses a different filesystem setup. Typically cloud-hosted S3 for AWS, minio for docker, and local filesystem for capistrano. The development environment uses docker-compose with minio. It can be hard to write tests to effectively test all scenarios in all environments so in order to ensure that we don't accidentally break one of these environments Avalon should have a docker-compose configuration that uses local filesystem in addition to the configuration that uses minio. The cloud-hosted S3 scenario should be mostly covered by minio.

We have servers running all of these environments (core servers and non-MCO servers use minio, MCO uses local filesystem, and demo.avalonmediasystem.org uses cloud-hosted S3) but it would be good to be able to test locally without having to wait until code reaches certain environments.

Done Looks Like

• docker-compose file includes the ability to pass a flag to use a local filesystem
• Add instructions on bringing the compose stack up with either options and for switching between them