Make make_enum simply create an Enumeration, not an EnumerationMeta
Make make_enum simply create an Enumeration, not an EnumerationMeta

This avoids a bunch of duplicated code as well as fixes __iter__ for
make_enum iterables.

Signed-off-by: Chris Lamb <711c73f64afdce07b7e38039a96d2224209e9a6c@playfire.com>

playfire/django-enumfield