Refactor test

[javierggt]

• Refactor code to move tests into a submodule.
• Pep8/flake8

[javierggt]

This PR is only two commits. It is easier to see the changes separately, because the second one is pep8/flake8.

[javierggt]

NOTE: I don't mind merging before/after the scm_version PR (#6). They are conflicting changes, but they are simple changes, so I can do it either way.

[taldcroft]

This was not passing tests locally because _norm was not included in the top-level from quatutil import *. So I just made that function public by changing _norm() to norm() .

Also, the setup.py was not resulting in a working (installable) distribution. I believe one needs to either call find_packages() or explicitly provide them in packages. What is confusing to me is that I looked at the source distribution tarball generated with 0d3912c and with my version dc0317a, and by eye I could not see an obvious difference. But only the latter will import after pip install . into a test env.

What we really should be doing is just deprecating this package completely and moving remaining bits of functionality into chandra_aca.transform. I'm opening an issue FWIW.

[taldcroft]

About removing this package, I just checked and it does get used in a lot of places. Probably not worth the effort, though we could port all functionality to chandra_aca.transform and recommend that for new code.

[taldcroft]

I have reviewed this and tested and it all looks good to me now, so merging.