Add test for WikiAssignmentOutput.build_talk_page_update
Add test for WikiAssignmentOutput.build_talk_page_update

This should hit the two lines lacking coverage in WikiAssignmentOutput.

WikiEducationFoundation/WikiEduDashboard,feelfreelinux/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,sejalkhatri/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,KarmaHater/WikiEduDashboard,alpha721/WikiEduDashboard,sejalkhatri/WikiEduDashboard,alpha721/WikiEduDashboard,Wowu/WikiEduDashboard,majakomel/WikiEduDashboard,Wowu/WikiEduDashboard,feelfreelinux/WikiEduDashboard,KarmaHater/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,WikiEducationFoundation/WikiEduDashboard,ragesoss/WikiEduDashboard,ragesoss/WikiEduDashboard,adamwight/WikiEduDashboard,sejalkhatri/WikiEduDashboard,MusikAnimal/WikiEduDashboard,alpha721/WikiEduDashboard,sejalkhatri/WikiEduDashboard,MusikAnimal/WikiEduDashboard,majakomel/WikiEduDashboard,WinnySilva/WikiEduDashboard,Wowu/WikiEduDashboard,WinnySilva/WikiEduDashboard,majakomel/WikiEduDashboard,feelfreelinux/WikiEduDashboard,adamwight/WikiEduDashboard,adamwight/WikiEduDashboard,ragesoss/WikiEduDashboard,Wowu/WikiEduDashboard,majakomel/WikiEduDashboard,KarmaHater/WikiEduDashboard,MusikAnimal/WikiEduDashboard,alpha721/WikiEduDashboard,WinnySilva/WikiEduDashboard,KarmaHater/WikiEduDashboard,MusikAnimal/WikiEduDashboard,sejalkhatri/WikiEduDashboard,feelfreelinux/WikiEduDashboard