Move test runner to makefile.
Add test for invalid class attribute access.
Add test_requirements.txt.
Add .travis.yml.
Add travis build icon to README.
Add coveralls support to travis.
Fix travis URL.
Add .coveralls.yml
Add LICENSE.
Add setup.py and setup.cfg with nosetests config.
Add coverage to travis.
Remove coveralls.yml.
Append coverage report
Remove "make test" from travis.
Add .coveragerc file and remove "coverage report" from travis.
Replace nose with pytest.
Add coverage badge to README.
Move operators to their own file. Add _and() and _or() operators.