Update supported django and python versions in readme
Update supported django and python versions in readme

django-silk/silk,jazzband/silk,django-silk/silk,jazzband/silk,mtford90/silk,crunchr/silk,django-silk/silk,crunchr/silk,mtford90/silk,crunchr/silk,mtford90/silk,mtford90/silk,crunchr/silk,jazzband/silk,jazzband/silk,django-silk/silk