Adds is_recoop field and related migration.
Adds reccop_id field and updates edition field, with migrations.
Adds management command to import ReCoop listings from Google Drive.
Renders special ReCoop listing information in template.
Adds fake sustainability@pomona.edu account for testing.
Freezes ReCoop purchases on days of the sale.
Sends specialized confirmation email for ReCoop purchases.
Replaces alpha filter with numeric pagination.
Exempts ReCoop listings from expiration task.
Hides ReCoop icon on mobile.
Enables breadcrumbs for SageBooks.
Adds pagination UI at bottom of page too.
Supports removal of books sold in-person at ReCoop.
Merge branch 'master' into staging