bump receptor
bump receptor

Submodule src/github.com/cloudfoundry-incubator/receptor 996a365..c493772:
  > document auth and CORS flow

Signed-off-by: Michael Fraenkel <ba3744c471de6199d0515ce197b77e0dafd711ed@us.ibm.com>

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