Use Docker by default for production

[wvengen]

The current Capistrano-based deployment setup is a bit complex. Many people doing deployment don't know Capistrano, it is a barrier to getting it running.

Using Docker would be a lot easier for most folks, so let's make that the primary deployment method.

• Finish Docker production setup
• Document using Docker for production
• Remove Capistrano files (they will become outdated - unless people are still using it)
• Clearing up development Docker docs and/or add a development Docker setup

Please respond if you are using Capistrano on production, and would like to continue doing so.

[wvengen]

There has been no response from Capistrano users, here nor on the mailing list, so I feel confident removing it.