Handle sql migrations

fixes #20 (closed)

I tried Alembic but it was too complex for our need.

This uses yoyo a simple tool where we can write migration in sql or python.

I kept the same way of migrating the database on startup, so the upgrade should seamless for running instances.

I quite like how it handles sql or python upgrade and downgrade

Note: I moved the camera table init to it's own migration to be able to populate the table in the same transaction