Merge pull request #12 from tristeng/master

added in delete rows function
improving version.py -- more robust
reorganizing tests so that they run under pytest and get called by `python setup.py test`
adding tests_require
Merge pull request #13 from diffeo/master

improving version.py -- more robust
fixing setup.py to include "mock" and "coverage"
Merge pull request #15 from diffeo/master

fixing setup.py to include "mock" and "coverage"
Merge remote-tracking branch 'upstream/master'