Prefer -dev services

The http://run.pivotal.io instance of Cloud Foundry has '-dev'
representations of all of the services exposed through the
marketplace.  In an effort to better identify our test usage, we want
to use these whenever they exist.  This change causes service creation
to prefer the use of '-dev' services if they are available, otherwise
fall back to using the standard service.

[#61402050]
Merge 61402050-dev-services to master

[Completes #61402050]
Support use of built-in buildpack

Previously, if no buildpack was specified via CF_BUILDPACK, the
buildpack from https://github.com/cloudfoundry/java-buildpack was
used.  This prevented the system test from running against the built-
in buildpack.  This change modifies that default, so that if
CF_BUILDPACK is not specified, the built-in buildpack is used instead.

[#62696164]
Merge 62696164-blessed-buildpack to master

[Completes #62696164]
Introduce tests for redis auto-reconfiguration

The bulk of changes refactor the existing structure to avoid code duplication
that would otherwise be caused when introducing a tests for new services