Bazel targets to run CF smoke and acceptance tests.

The smoke, brain, and acceptance tests can be run after Kubecf deployment has completed, via:

bazel run //testing/smoke_tests
bazel run //testing/brain_tests
bazel run //testing/acceptance_tests

The acceptance tests can be limited to specific suites of interest, as explained in the linked document.

Last modified December 19, 2019: Integrating remaining existing docs (961159c)