Remove a 2.6ism that slipped in.
Merge pull request #130 from candlepin/awood/remove-26ism

Remove a 2.6ism that slipped in.
Automatic commit of package [python-rhsm] release [1.13.2-1].
Add Fedora 21 branch to releaser.
Add releaser for EPEL 7.
Make more use of setup.py.

Use 'setup.py flake8' for pep8/pyflakes.
Make 'make clean' clean more.
Add python requirements files.
Add misc build/test debris to .gitignore
Add 'make docs' target for sphinx.
Specify we only want to run unit tests by default.
Mark all the functional tests as 'functional'
Use '!functional' as the default test filter

--where works, but seems to confuse coverage
collection.
'make clean' targets runs setup.py clean --all