Bump src/collector, src/hm9000

Bump cloudfoundry/collector:
  Onsi Fakhouri and Phan Le:
     added hm9000 handler ( Travis Success: https://travis-ci.org/cloudfoundry/collector/builds/12439881 )
Bump cloudfoundry/hm-workspace:
  Onsi Fakhouri and Phan Le:
     metrics server registers with collector and actually serves a varz endpoint; bump testing framework