Add Shots App

[Kryses]

Add the shots app for managing shots.

Models

Shot

• name

• scene

• sequence

• pipelines

• asset_instances

• name, sequence, scene unique together

Scene

• name

Sequence

• name

AssetInstance

• shot

• asset

• instance_count

• shot, asset unique together

[Kryses]

I'm removing this from the milestone for. I'd like to see how our setup works out for assets before plunging into shots. Shots can be a feature we add later.