LP1804066: Don't allow overlapping bookings

LP1804066: Don't allow overlapping bookings

Note: this includes a change to the concerto test data.  You will
need to reload the concerto data set before successfully running
the included live tests.

To test:

1. Go to the Booking > Create Reservation
2. Choose resource by type: find a resource type that only has a single resource for ease of testing.
3. Select a time slot and press Create Reservation
4. Select a patron.
5. In a second tab, repeat the steps, being sure to select the same resource and time slot, but a
different patron.
6. Press Confirm Reservation in one of your tabs.
7. Confirm that the reservation was made correctly.
8. Press Confirm Reservation in the second tab.
9. Confirm that the conflicting booking does not go through.

Signed-off-by: Jane Sandberg <js7389@princeton.edu>
Signed-off-by: Susan Morrison <smorrison@georgialibraries.org>
Signed-off-by: Steven Mayo <smayo@georgialibraries.org>
Signed-off-by: Terran McCanna <tmccanna@georgialibraries.org>