Remove Django 1.4 from supported versions in README.
Remove Django 1.4 from supported versions in README.

biomassives/mezzanine,douglaskastle/mezzanine,frankier/mezzanine,orlenko/sfpirg,douglaskastle/mezzanine,ZeroXn/mezzanine,joshcartme/mezzanine,ZeroXn/mezzanine,wrwrwr/mezzanine,frankier/mezzanine,sjuxax/mezzanine,stbarnabas/mezzanine,frankier/mezzanine,molokov/mezzanine,stephenmcd/mezzanine,industrydive/mezzanine,tuxinhang1989/mezzanine,industrydive/mezzanine,adrian-the-git/mezzanine,gbosh/mezzanine,dekomote/mezzanine-modeltranslation-backport,jerivas/mezzanine,nikolas/mezzanine,viaregio/mezzanine,sjuxax/mezzanine,dekomote/mezzanine-modeltranslation-backport,viaregio/mezzanine,saintbird/mezzanine,cccs-web/mezzanine,spookylukey/mezzanine,dustinrb/mezzanine,promil23/mezzanine,biomassives/mezzanine,douglaskastle/mezzanine,AlexHill/mezzanine,theclanks/mezzanine,readevalprint/mezzanine,Skytorn86/mezzanine,wrwrwr/mezzanine,jjz/mezzanine,theclanks/mezzanine,gradel/mezzanine,geodesign/mezzanine,geodesign/mezzanine,dekomote/mezzanine-modeltranslation-backport,cccs-web/mezzanine,Cicero-Zhao/mezzanine,Skytorn86/mezzanine,wyzex/mezzanine,biomassives/mezzanine,Kniyl/mezzanine,guibernardino/mezzanine,gradel/mezzanine,stephenmcd/mezzanine,molokov/mezzanine,webounty/mezzanine,dsanders11/mezzanine,jjz/mezzanine,webounty/mezzanine,joshcartme/mezzanine,vladir/mezzanine,orlenko/plei,agepoly/mezzanine,wbtuomela/mezzanine,christianwgd/mezzanine,scarcry/snm-mezzanine,promil23/mezzanine,gbosh/mezzanine,sjdines/mezzanine,christianwgd/mezzanine,AlexHill/mezzanine,jerivas/mezzanine,orlenko/sfpirg,orlenko/plei,emile2016/mezzanine,dovydas/mezzanine,eino-makitalo/mezzanine,ryneeverett/mezzanine,frankchin/mezzanine,Kniyl/mezzanine,SoLoHiC/mezzanine,ryneeverett/mezzanine,sjdines/mezzanine,saintbird/mezzanine,SoLoHiC/mezzanine,readevalprint/mezzanine,scarcry/snm-mezzanine,adrian-the-git/mezzanine,gbosh/mezzanine,wyzex/mezzanine,theclanks/mezzanine,eino-makitalo/mezzanine,mush42/mezzanine,Cajoline/mezzanine,PegasusWang/mezzanine,gradel/mezzanine,wyzex/mezzanine,dustinrb/mezzanine,wbtuomela/mezzanine,mush42/mezzanine,damnfine/mezzanine,tuxinhang1989/mezzanine,orlenko/plei,fusionbox/mezzanine,nikolas/mezzanine,christianwgd/mezzanine,saintbird/mezzanine,dsanders11/mezzanine,agepoly/mezzanine,Cajoline/mezzanine,Kniyl/mezzanine,dsanders11/mezzanine,Cajoline/mezzanine,dovydas/mezzanine,adrian-the-git/mezzanine,ryneeverett/mezzanine,frankchin/mezzanine,frankchin/mezzanine,batpad/mezzanine,guibernardino/mezzanine,viaregio/mezzanine,eino-makitalo/mezzanine,orlenko/sfpirg,nikolas/mezzanine,stephenmcd/mezzanine,emile2016/mezzanine,tuxinhang1989/mezzanine,vladir/mezzanine,dustinrb/mezzanine,stbarnabas/mezzanine,ZeroXn/mezzanine,mush42/mezzanine,fusionbox/mezzanine,Cicero-Zhao/mezzanine,damnfine/mezzanine,molokov/mezzanine,sjdines/mezzanine,scarcry/snm-mezzanine,jerivas/mezzanine,spookylukey/mezzanine,dovydas/mezzanine,webounty/mezzanine,spookylukey/mezzanine,damnfine/mezzanine,PegasusWang/mezzanine,jjz/mezzanine,wbtuomela/mezzanine,agepoly/mezzanine,industrydive/mezzanine,vladir/mezzanine,PegasusWang/mezzanine,readevalprint/mezzanine,sjuxax/mezzanine,batpad/mezzanine,geodesign/mezzanine,emile2016/mezzanine,SoLoHiC/mezzanine,joshcartme/mezzanine,promil23/mezzanine,Skytorn86/mezzanine