Use switchblade for integration testing

[ryanmoran]

"Switchblade is an integration testing framework for Cloud Foundry v2b buildpacks. It enables test authors to write tests once, and then run them either against a real Cloud Foundry, or their local Docker daemon."

Using switchblade in our integration testing should greatly improve the ability to rapidly iterate during buildpack development.

There is already an existing attempt to do this work on this branch: https://github.com/cloudfoundry/python-buildpack/tree/use-switchblade

[ryanmoran]

@brayanhenao since you had started this work, is there any other context needed here or understanding of the state this WIP branch is in?

[brayanhenao]

@ryanmoran That branch was an attempt (which I abandoned due to lack of time) to use the same structure you had used for go/node in switchblade. There is not much progress, so the person who will be in charge of doing this migration either can re-use the branch or start from scratch.

[robdimsdale]

Closed via #746