Added test to ensure warnings that don't sub-class from Astropy don't get interpreted by the logger.
Added test to ensure warnings that don't sub-class from Astropy don't get interpreted by the logger.

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