Cleanup of solar_system following comments by @eteq.
Cleanup of solar_system following comments by @eteq.

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