'Chaos' is a new a group of test that validates behavior in presence of
random failures.
Overview:
- Introduce a 'Chaos Monkey' controller which can unleash a monkey
against a test cluster.
- Introduce a monkey of type 'ClusterBouncer' which stops and restarts
nodes according to some configuration
- Add 2 example tests, they ensure a cluster can survive some amount of
nodes bouncing
- Configure the build to skip chaos tests unless explicitly requested
- Add some test utility functions
