Update models.py
Update models.py

This fixes day light saving issue.  It seems that created_at is coming with timezone 0000  UTC, so I would like to make ti timezoneaware using just utc.  Django templates shows datetime ok with timesince without one hour error
fusionbox/mezzanine,Kniyl/mezzanine,damnfine/mezzanine,sjuxax/mezzanine,wbtuomela/mezzanine,Cicero-Zhao/mezzanine,SoLoHiC/mezzanine,tuxinhang1989/mezzanine,vladir/mezzanine,readevalprint/mezzanine,industrydive/mezzanine,promil23/mezzanine,SoLoHiC/mezzanine,AlexHill/mezzanine,saintbird/mezzanine,fusionbox/mezzanine,promil23/mezzanine,industrydive/mezzanine,biomassives/mezzanine,SoLoHiC/mezzanine,tuxinhang1989/mezzanine,geodesign/mezzanine,wyzex/mezzanine,ZeroXn/mezzanine,promil23/mezzanine,jjz/mezzanine,dekomote/mezzanine-modeltranslation-backport,wyzex/mezzanine,readevalprint/mezzanine,gradel/mezzanine,saintbird/mezzanine,viaregio/mezzanine,douglaskastle/mezzanine,joshcartme/mezzanine,eino-makitalo/mezzanine,gradel/mezzanine,Cajoline/mezzanine,molokov/mezzanine,sjdines/mezzanine,adrian-the-git/mezzanine,Cajoline/mezzanine,nikolas/mezzanine,dsanders11/mezzanine,industrydive/mezzanine,readevalprint/mezzanine,dovydas/mezzanine,spookylukey/mezzanine,dsanders11/mezzanine,emile2016/mezzanine,ZeroXn/mezzanine,frankchin/mezzanine,dekomote/mezzanine-modeltranslation-backport,theclanks/mezzanine,damnfine/mezzanine,emile2016/mezzanine,Skytorn86/mezzanine,mush42/mezzanine,geodesign/mezzanine,nikolas/mezzanine,frankier/mezzanine,dovydas/mezzanine,eino-makitalo/mezzanine,Skytorn86/mezzanine,wbtuomela/mezzanine,theclanks/mezzanine,Cicero-Zhao/mezzanine,stephenmcd/mezzanine,jerivas/mezzanine,jjz/mezzanine,wbtuomela/mezzanine,christianwgd/mezzanine,mush42/mezzanine,douglaskastle/mezzanine,biomassives/mezzanine,sjdines/mezzanine,theclanks/mezzanine,adrian-the-git/mezzanine,douglaskastle/mezzanine,PegasusWang/mezzanine,stephenmcd/mezzanine,frankchin/mezzanine,dustinrb/mezzanine,sjdines/mezzanine,ryneeverett/mezzanine,eino-makitalo/mezzanine,Skytorn86/mezzanine,biomassives/mezzanine,nikolas/mezzanine,damnfine/mezzanine,frankier/mezzanine,ZeroXn/mezzanine,dsanders11/mezzanine,PegasusWang/mezzanine,dovydas/mezzanine,vladir/mezzanine,joshcartme/mezzanine,Cajoline/mezzanine,ryneeverett/mezzanine,christianwgd/mezzanine,mush42/mezzanine,saintbird/mezzanine,ryneeverett/mezzanine,jerivas/mezzanine,jjz/mezzanine,PegasusWang/mezzanine,sjuxax/mezzanine,molokov/mezzanine,webounty/mezzanine,spookylukey/mezzanine,sjuxax/mezzanine,dekomote/mezzanine-modeltranslation-backport,christianwgd/mezzanine,viaregio/mezzanine,tuxinhang1989/mezzanine,dustinrb/mezzanine,dustinrb/mezzanine,Kniyl/mezzanine,joshcartme/mezzanine,geodesign/mezzanine,stephenmcd/mezzanine,webounty/mezzanine,jerivas/mezzanine,wyzex/mezzanine,frankchin/mezzanine,spookylukey/mezzanine,AlexHill/mezzanine,viaregio/mezzanine,webounty/mezzanine,adrian-the-git/mezzanine,molokov/mezzanine,emile2016/mezzanine,Kniyl/mezzanine,vladir/mezzanine,frankier/mezzanine,gradel/mezzanine