Refactored to "make test" on containers.

The way we ran the controller tests was contrived, so this refactoring reduces the basic testing contract to "get the code, build the container, run 'make test' in the container" and creates Schedulers and Builders for each Docker container-based project in the Deis ecosystem. (Exceptions currently are "base", "data", "slugbuilder", which don't and may not ever have a "make test," so they just get "docker build.")

I will separately create a PR for deis/controller 'make test' to execute the current set of Django tests in-container so we are back to parity with our old test setup.

Other TODO items are: integration tests as a buildbot Triggerable after all unit tests succeed, client binary builders, EC2 AMI builder/distributor tasks.

This can be merged any time. Our Travis CI integration still runs and reports on the server...err *controller* tests the old way, and that number is still valid so this will not disturb our public-facing badges while we continue improving our CI system.