Add test to compare tz naive and tz aware times
Add test to compare tz naive and tz aware times

EdwardJKim/nbgrader,dementrock/nbgrader,jhamrick/nbgrader,EdwardJKim/nbgrader,jupyter/nbgrader,ellisonbg/nbgrader,jupyter/nbgrader,dementrock/nbgrader,MatKallada/nbgrader,alope107/nbgrader,ellisonbg/nbgrader,alope107/nbgrader,MatKallada/nbgrader,EdwardJKim/nbgrader,EdwardJKim/nbgrader,ellisonbg/nbgrader,jhamrick/nbgrader,jupyter/nbgrader,jupyter/nbgrader,jupyter/nbgrader,modulexcite/nbgrader,ellisonbg/nbgrader,modulexcite/nbgrader,jdfreder/nbgrader,jhamrick/nbgrader,jhamrick/nbgrader,jdfreder/nbgrader