Updating a package on PyPi, testing and etiquette

[Rob Gaddi]

So I've got a package I put up on PyPi a while back (ctypes-bitfield, if 
it matters).  For version 0.2.6 I had access to some older versions of 
Python and was able to run my test suite on Python 2.6 and 3.0.

Well, I don't have them anymore.  I've got no access right now to 
anything older than 2.7 and 3.2, and my primary development environment 
is 3.4.  But I've also updated the package to support what I consider to 
be some really nice new functionality.  So, it comes down to two 
questions:

A) Is there any easy way to test against an older version of Python?  
Preferably without trying to install entire old environments and keep 
them nicely isolated from my actual doing work?  I'm running Ubuntu for 
what difference that makes.

B) If I can't manage that, what's the etiquette behind having later 
versions of a module break compatibility with older versions of Python.  
I've avoided using features I know are newer, like yield from and Enums, 
but I won't swear it'll work on 3.0 if I can't test it that way.

-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.