Display billing details on new site creation.
Fixed header not appearing in modal forms
Starting working on dynamically adding domains to the site form.
Since Stripe doesn't support multiple subscriptions per client, we have to roll our own.  Added a subscriptions model to handle.
Added untracked files.
Corrected subscriptions to pull those where next_bill_date is the current date.
Updated invoice line item to show primary domain, created necessary associations.
Added devise for auth.  For now, only auth admin users.  V2.0 will have client dashboard.