bump nsync
bump nsync

Submodule src/github.com/cloudfoundry-incubator/nsync a2fd25c..8ef305a:
  > Increase the timeout to wait for domain freshness

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release