Add numpy import to docstring
Add numpy import to docstring

mhvk/astropy,astropy/astropy,saimn/astropy,saimn/astropy,pllim/astropy,StuartLittlefair/astropy,pllim/astropy,pllim/astropy,lpsinger/astropy,lpsinger/astropy,StuartLittlefair/astropy,larrybradley/astropy,mhvk/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,astropy/astropy,pllim/astropy,astropy/astropy,larrybradley/astropy,lpsinger/astropy,saimn/astropy,lpsinger/astropy,saimn/astropy,mhvk/astropy,larrybradley/astropy,saimn/astropy,pllim/astropy,mhvk/astropy,larrybradley/astropy,lpsinger/astropy,astropy/astropy,astropy/astropy,larrybradley/astropy,mhvk/astropy