fix(api/models/app): Catch unhandled error (deis#1317)

Fix for deis#1313

An unhandled exception in ns.create due to "Conflict
namespaces" will
wipe out an entire namespace. I've added a catch here to
protect against
that occurring.

Merge pull request deis#1314 from mboersma/update-requirements

chore(requirements): update support libraries

Merge pull request deis#1312 from mboersma/update-django

chore(requirements): update Django to v1.11.3

RBAC support (deis#1292)

With this change deis-controller became available to work in RBAC-only clusters

Merge pull request deis#1293 from mboersma/mit

ref(LICENSE): switch to MIT license

Merge pull request deis#1291 from mboersma/update-pyopenssl

chore(requirements): update pyOpenSSL to v17.0.0

Merge pull request deis#1271 from mboersma/test-in-docker

feat(Makefile,rootfs): run unit and style tests in container

Merge pull request deis#1255 from mboersma/default-admin-only-registr…

…ation

fix(charts): default registration mode to "admin_only"

Merge pull request deis#1245 from mboersma/update-reqs

chore(requirements): update ldap, drf, and requests-toolbelt

fix(charts): reference registry-proxy on 127.0.0.1 (deis#1239)

On some providers, "localhost" is not set up on the host network. explicitly calling the loopback
address fixes this.