added calculation method for status

[nathandunn]

fixes #25

• [x] collect stats from ALL TPM files
• [x] fix output out into a gene map stat (duplicated now)
• [x] calculate TPM files for gene map stats to export Z-files
  • [x] write test for TpmStat constructor
  • [x] write test to test Z-value calculator
• [ ] send to Jing for upload via S3:
  • [x] gzip
  • [ ] upload to S3 in own directory
  • [ ] make public
• integrate new values into defaultGeneSet.json - a separate ticket