Added comment in command.py about install test and runtime deps.
Added comment in command.py about install test and runtime deps.

joergdietrich/astropy,dhomeier/astropy,tbabej/astropy,joergdietrich/astropy,larrybradley/astropy,DougBurke/astropy,kelle/astropy,pllim/astropy,saimn/astropy,mhvk/astropy,StuartLittlefair/astropy,bsipocz/astropy,saimn/astropy,stargaser/astropy,larrybradley/astropy,stargaser/astropy,dhomeier/astropy,mhvk/astropy,StuartLittlefair/astropy,kelle/astropy,AustereCuriosity/astropy,AustereCuriosity/astropy,mhvk/astropy,funbaker/astropy,lpsinger/astropy,MSeifert04/astropy,tbabej/astropy,StuartLittlefair/astropy,joergdietrich/astropy,tbabej/astropy,larrybradley/astropy,DougBurke/astropy,bsipocz/astropy,larrybradley/astropy,pllim/astropy,funbaker/astropy,saimn/astropy,aleksandr-bakanov/astropy,aleksandr-bakanov/astropy,MSeifert04/astropy,astropy/astropy,lpsinger/astropy,astropy/astropy,kelle/astropy,dhomeier/astropy,pllim/astropy,funbaker/astropy,dhomeier/astropy,saimn/astropy,kelle/astropy,pllim/astropy,tbabej/astropy,aleksandr-bakanov/astropy,bsipocz/astropy,AustereCuriosity/astropy,lpsinger/astropy,lpsinger/astropy,astropy/astropy,AustereCuriosity/astropy,kelle/astropy,mhvk/astropy,mhvk/astropy,StuartLittlefair/astropy,bsipocz/astropy,StuartLittlefair/astropy,dhomeier/astropy,MSeifert04/astropy,pllim/astropy,astropy/astropy,funbaker/astropy,DougBurke/astropy,DougBurke/astropy,MSeifert04/astropy,aleksandr-bakanov/astropy,joergdietrich/astropy,stargaser/astropy,saimn/astropy,astropy/astropy,stargaser/astropy,larrybradley/astropy,AustereCuriosity/astropy,tbabej/astropy,lpsinger/astropy,joergdietrich/astropy