releasing pykickstart-3

Lately, I've been working on a new major version of pykickstart that
will be incompatible with the current version.  This incompatibility is
because I've moved to the python argparse module from the deprecated
optparse.  The boring details are here:

https://github.com/rhinstaller/pykickstart/blob/master/docs/2to3

Anyway, pykickstart has a rich tradition of not screwing users over.
I'd like to continue that when I release major version 3.  However I
don't really know how to go about doing it while still leaving
pykickstart-2 around for people to take their time moving from.

I guess the typical way is to create a new package that can be installed
alongside the old one, right?  I kind of hate that.  Are there other
options?

- Chris