Fix database connection

This is the code that's currently running on Doorbot.

Here's what the changes do:

- Fix the database connection (it wasn't working as written).
- Upgrade all gems to latest versions
- Remove tux dependency
- Make `unlocker` not a global (it's no longer necessary)
- Remove some unused code
- Add some log messages on boot
- Remove references to RACK_ENV
- ignore run.sh
- Whitespace cleanup