New setup.py, using six for urllib.

Copied setup.py from Flask-JIRA-Helper.
Using six library instead of my ugly conditional where the imports are.
Added flake8 and pylint to setup.py.

Also made read_config() more testable. It only needs the app.config
dict, not the whole app instance.
Added coveralls support in TravisCI.
Added Coverage badge to README.
Tested read_config().
100% test coverage.
Updated to 0.1.2.
Merge pull request #1 from Robpol86/more_tests

100% test coverage.