add test for nested dtype numpy array
add test for nested dtype numpy array

cpcloud/datashape,quantopian/datashape,cowlicks/datashape,ContinuumIO/datashape,cpcloud/datashape,cowlicks/datashape,blaze/datashape,quantopian/datashape,llllllllll/datashape,blaze/datashape,llllllllll/datashape,ContinuumIO/datashape