Added test for param_cov
Added test for param_cov

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