Bump src/nsync, src/stager, src/tps

Bump cloudfoundry-incubator/nsync:
  Steve Powell:
     Autowire dropsonde for go metrics ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/nsync/builds/34243470 )
  Alex Suraci:
     add concourse config ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/nsync/builds/33952713 )
     wait for NATS to be up on start-up ( Travis Unknown )
     fix flaky freshness test ( Travis Unknown )
Bump cloudfoundry-incubator/stager:
  Steve Powell:
     Forgot to bump godeps for dropsonde ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/stager/builds/34242574 )
     Autowire dropsonde for go metrics ( Travis Failed: https://travis-ci.org/cloudfoundry-incubator/stager/builds/34242507 )
Bump cloudfoundry-incubator/tps:
  Steve Powell:
     Autowire dropsonde for go metrics ( Travis Success: https://travis-ci.org/cloudfoundry-incubator/tps/builds/34243604 )