Name snapshots based on the type of schedule

Add support for naming imagess appropriately depending on if
the schedule is for a daily or a weekly snapshot.

Removed a couple of functional tests that weren't really functional and were redundant with similar unit tests.
previously the prefix was 'Daily-' but now the prefix is either 'Daily' or 'Weekly'. Since the hyphen is no longer a part of the prefix string this just takes it into account here.