Added retries to docker install playbook to help with sporadic failures talking to yum.
Added retries to docker install playbook to help with sporadic failures talking to yum.

StanfordBioinformatics/loom,StanfordBioinformatics/loom,StanfordBioinformatics/xppf,StanfordBioinformatics/xppf,StanfordBioinformatics/loom,StanfordBioinformatics/loom,StanfordBioinformatics/xppf,StanfordBioinformatics/xppf