Add "Minecraft server has started" message

[jack-michaud]

Background

There are three phases to starting up a new Minecraft server.

• Provisioning a VPS (terraform)
• Installing the server (ansible)
• Starting the server

There are success/fail messages after Provisioning, Installation, but not for starting the server. This last step is sometimes the longest for larger modpacks.

Story

As a user, I want to be informed when the server has started so I know I can log in. This will help me be sure that the server hasn't crashed in the last leg of the startup phase.

Deliverables

• Create way to store persistent SSH connection (branch: bridge has some of this work started with the Bridge struct).
• Tail the logs and look for success message. Send a success message if it succeeds
• Tail the logs and look for failure message. Send a failure message if it fails with actions to resolve the issue (like make an issue on github)

This is a big issue. Might break it up into smaller bits. The first bullet alone is a big issue honestly.