itertools.product is Python 2.6 or later only

[Martin Packman]

README claims 2.4+ is supported, but the testscenarios.scenario module depends on itertools.product which requires 2.6 at least:
<http://docs.python.org/library/itertools.html#itertools.product>

The multiply_scenarios function doesn't actually benefit from iterating rather than listing all the results at once. Rewriting to not use the helper may be just as easy as including a compatibility implementation.

[Robert Collins (lifeless)]

care to put a patch together?

[Robert Collins (lifeless)]

Changed the docs to say 2.6+.