Added environment variable lookups to task runner playbook.
Added environment variable lookups to task runner playbook.

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