Make Stars / Ansible deployment more robust

[stevencox]

Start from CentOS7 VMs and configure masters with

• Zookeeper
• Mesos
• Marathon
• Chronos
• Mesos-DNS

Workers with

• Spark
• Livy
• Python 2 virtual environemnt
• Python 3 virtual environment
• Mesos Worker

Since this roughly exists the work will likely be:

• Test / verify
• Installing a Yum repo for JDK install is buggy
• We don't yet have a Python 2 virtual env
• Both virtual envs need to be accessible via Spark