Updated tests to check for th tags instead of td tags within thead blocks
Updated tests to check for th tags instead of td tags within thead blocks

tw4452852/blackfriday,tianon/debian-golang-blackfriday,linuxerwang/blackfriday,jmptrader/blackfriday,linuxerwang/blackfriday,kristofer/blackfriday,beni55/blackfriday,elian0211/blackfriday,Depado/blackfriday,jacobxk/blackfriday,ArtemTeleshev/blackfriday,lfn3/blackfriday,rtfb/blackfriday,treejames/blackfriday,beni55/blackfriday,kristofer/blackfriday,elian0211/blackfriday,lfn3/blackfriday,tianon/debian-golang-blackfriday,JackKnifed/blackfriday,icco/blackfriday,DimShadoWWW/blackfriday,tw4452852/blackfriday,apiaryio/blackfriday,icco/blackfriday,DimShadoWWW/blackfriday,Depado/blackfriday,apiaryio/blackfriday,JackKnifed/blackfriday,treejames/blackfriday,ckeyer/blackfriday,Ronmi/blackfriday,rtfb/blackfriday,jacobxk/blackfriday,Go-ApiBlueprint-Go/blackfriday,Ganners/blackfriday,ArtemTeleshev/blackfriday,Ganners/blackfriday,Ronmi/blackfriday,jmptrader/blackfriday,ckeyer/blackfriday,Go-ApiBlueprint-Go/blackfriday