Use pip to get more recent versions of pyflakes and pep8 than are in 12.04, the version currently running on Travis

Signed-off-by: Michael McCracken <mike.mccracken@canonical.com>
use pyflakes not pyflakes3 for pip-installed systems and force pyflakes to run with python3 on apt-installed systems

Signed-off-by: Michael McCracken <mike.mccracken@canonical.com>
use nosetests with no 3, so pip-installs like travis work.

Signed-off-by: Michael McCracken <mike.mccracken@canonical.com>
Merge pull request #4 from mikemccracken/fix-travis-pyflakes

Fix pip, pyflakes and nose test running on travis CI