Create urls/views/templates for dev-only views

Our designers find it helpful to be able to stub out simple views that aren't ready
to be seen for production yet, and check them into version control so that other
people can see them and provide feedback. This commit introduces a few new files
and directories for this purpose, as well as a sample view that will only be seen
in dev mode, and never in production.
pylint cleanup
Merge pull request #546 from edx/db/dev-views

Create urls/views/templates for dev-only views