make tests py 3.x compliant via `unicode`->`six.text_type`
make tests py 3.x compliant via `unicode`->`six.text_type`

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