serverspec aims to run service validation during TripleO/Puppet
deployment by using step-by-step workflow.
Example: step 1 contains MySQL Galera cluster, so Puppet will take care
of configuration and serverspec will ensure MySQL is actually up and
running, otherwise we consider the stack failed.
This patchs:
* Installs serverspec by using Gem (source).
For now, there is no package for any distribution, so until we have one,
let's use source method by running `gem install`, that will take care of
serverspec and dependencies.
* Installs serverspec-tests from rdo-management.
For now, serverspec-tests are hosted on github/rdo-management, so
until we have packaging, we use source install method.
Change-Id: I8efc9a2278e972fe0c61e12823a9250a4a1bc27d