Have release.py run tests too
Have release.py run tests too

EdwardJKim/nbgrader,EdwardJKim/nbgrader,EdwardJKim/nbgrader,jhamrick/nbgrader,jupyter/nbgrader,jupyter/nbgrader,jhamrick/nbgrader,ellisonbg/nbgrader,ellisonbg/nbgrader,ellisonbg/nbgrader,jupyter/nbgrader,ellisonbg/nbgrader,EdwardJKim/nbgrader,jupyter/nbgrader,jhamrick/nbgrader,jupyter/nbgrader,jhamrick/nbgrader