fixing yaml key typo for fleet.public-ip

According to https://coreos.com/docs/cluster-management/setup/cloudinit-cloud-config/ it should be "public-ip" not "public_ip"
fix(docs): update links to buildpacks included with Deis
Merge pull request #1790 from mboersma/1782-fix-buildpacks-links

fix(docs): update links to buildpacks included with Deis
chore(controller): update Django to 1.6.7 bugfix release

https://www.djangoproject.com/weblog/2014/sep/02/release-17-final/
Merge pull request #1792 from mboersma/update-django-167

chore(controller): update Django to 1.6.7 bugfix release
Merge pull request #1787 from alex-sherwin/patch-1

fixing yaml key typo for fleet.public-ip