Add basic flask-peewee integration

1. Define models in peewee
2. Add db manage commands
3. Remove model definitions in sqlalchemy

This commit breaks xponentialy.tasks, need to fix later
Add admin

1. Register xp models in Admin portal
2. Add a CLI for creating admin users
Admin config tweaks

1. Change branding name in Admin to Xponentialy
2. Hide oauth_secret in admin
Add related name for relationships
Add customize auth
Change create admin command to create user
Add relation between house and company
Add peewee admin and rest API
Use flask-peewee as API/Auth/Admin backend