Make deployment robust

[ihodes]

• Fix postgres connection leaks

[arahuja]

Perhaps related, but after the redeployment and submitting a run I see:

File "/home/cycledash/cycledash/venv/lib/python2.7/site-packages/requests/adapters.py", line 375, in send
    raise ConnectionError(e, request=request)
ConnectionError: HTTPConnectionPool(host='demeter.hpc.mssm.edu', port=14000): Max retries exceeded with url: /webhdfs/v1/datasets/vcfs/sample.strelka.indels.passed.vcf?op=OPEN&user.name=cycledash (Caused by <class 'socket.gaierror'>: [Errno -5] No address associated with hostname)

[ihodes]

Good to know; that may be a WebHDFS issue (/cc @zgiles)?