Exclude compiled byte code from distributions

[sbraz]

Hi, the current PyPI tarball contains a __pycache__ folder, this causes tests to fail:

import file mismatch:
imported module 'test_utils' has this __file__ attribute:
  /home/tom/Docs/Programming/dominate/tests/test_utils.py
which is not the same as the test file we want to collect:
  /var/tmp/portage/dev-python/dominate-2.3.0/work/dominate-2.3.0/tests/test_utils.py
HINT: remove __pycache__ / .pyc files and/or use a unique basename for your test file modules
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 3 errors during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[coveralls]

Coverage remained the same at 96.661% when pulling 2efe049 on sbraz:manifest into d05a4ad on Knio:master.

[Knio]

Thanks!