tests with molecule 2.10 on Ubuntu and centos

[lhoss]

I am happy to announce I got a first working version of molecule v2 tests ready for another PR (once my other PRs are merged 👍 )

A quick Roadmap of my plans:

• [x] test on various distros (already implemented on Ubuntu 16.04, centos7)
• [x] basic tests verifying the spark deployment incl. the supported config files
• [ ] tests for deployed spark-services (needs a PR first of spark-services)
• [ ] tests of a small spark cluster (1. using standalone spark master/agents, tough we ran spark on mesos)

Feel free to comment with ideas