Add default arg for class create methods

No reason that ClassName.create! shouldn't work.

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Persist should return true

Otherwise, it halts the callback chain.

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Return false for destroy if already destroyed

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Base specs

Signed-off-by: Stephen Celis <stephen@stephencelis.com>