Loans and renewals should use the appointment slots calendar to determine when an item is due

[jim]

The app currently has a hard-coded list of days that the library is open that are used to decide when new loans will be due (there's no point in having something due on a day the library isn't open). Unfortunately, this doesn't take into account the library's changing schedule or that it is sometimes closed for holidays.

We pull events from a Google calendar to determine when appointments can be scheduled, and using this data, we should be able to have the end dates for loans be more intelligent.

Some things to consider:

• We might want to update how far in the future we generate appointment slots in bin/reset so that folks can renew items a few times without the app breaking.
• How should we handle a case where there aren't any upcoming appointment slots? We'll need to add some error handling to places where there currently isn't any.

Working on this requires that you have a Google calendar created for development and an API key that provides access to it.

Questions

• Is there any reason we shouldn't do this? Another option is to make the "days open" configurable, but it seems like that would be a worse experience than the above.