Add service-identity to requirements.txt.

This closes: https://github.com/m-lab-tools/ooni-support/issues/41
Implement policy aware bouncing support in the backend
Review of policy aware changes
Use the correct txtorcon API depending on the software version.

This fixes: https://trac.torproject.org/projects/tor/ticket/12747
Merge pull request #53 from TheTorProject/fix/12747

Use the correct txtorcon API depending on the software version.
Update travis.yml to run unittests.
Use requirements.txt not .requirements.txt
Comment out notifications.
convert README to .rst
Add information about what oonib is.
Run coveralls when the tests have been run.
Fix markup
Add coveralls descriptor to repo
Fix code coverage badge
Bug in test_bouncer fixed
Tell coveralls of the coveragerc
Implement policy aware bouncing support in the backend
Review of policy aware changes
Bug in test_bouncer fixed
Fix compatibility with txtorcon >= 0.10.0