Add some basic tests for nbgrader fetch
Add some basic tests for nbgrader fetch

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