implementing testing framework

[lxkain]

right now, there is no test coverage on any of the code, and given the number of broken commits I've submitted, we should start to implement test coverage.

Given the current development, and popularity, I suggest we use py.test

there is an extension to pytest, for qt guis pytest-qt which is installable via pip

unfortunately pytest-qt is not compatible w/ qtpy yet however given that we are not compatible w/ pyside, pyqt4 or pyside2, we could switch the imports back to pyqt5 to implement pytest-qt

[j9ac9k]

Going to add the high priority and help wanted tags, as the lack of testing is hugely slowing down development, and I'm not sure how to even get started here.