Make contact_email default to '' in DB
Fix for cases with several contact_emails
Default to reservation creator to make occurrences
Add some info in Exception
Add occurrence creation in fixture
Add availabilty test for Room.find_with_filters
Remove useless check

There are no rooms with no owner.
Test Room.has_live_reservation
Add more generic find_with_filters testcase
Removed unused RepeatFrequency.YEAR
Fix default repeat_interval in create_reservation