Fix 405 Not Allowed when downloading app from cc_ng

The nginx.conf in cf-release should allow droplets and buildpack download thru cc_ng.
Merge branch 'pr/112'
Move collector pointer forward:
Alex Suraci (1):
      Merge pull request #2 from cloudfoundry/add_dea_logging_agent

Maria Shaldibina and aram price (1):
      Add contributing guide

Mike Gehard (1):
      New collector for loggregator dea agent

Signed-off-by: Matthew McNew <mmcnew@pivotallabs.com>