added python 3.5 on travis and removed unsupported django 1.6
added python 3.5 on travis and removed unsupported django 1.6

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