Simplify can_cast test for numpy 1.5
Simplify can_cast test for numpy 1.5

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