Code review comment for lp:~clint-fewbar/pyjuju/fix-tests-without-aws-access-key-id

I think I see the problem a little clearer now, and the real issue is that there are actually bugs in some assumptions made in the EC2 provider about how txaws works.. so this will need more thought. For now I'll keep this patch in the package build steps so we can run all the other tests, but the bug itself is perhaps a symptom of something much deeper.