bump receptor httpauth

Submodule src/github.com/cloudfoundry-incubator/receptor 575cb5a..2f0ab9b:
  > Remove some internal logic from API package
  > Add API client
  > Set content-{length,type} headers when returning JSON
  > return 409 Conflict when a created Task guid already exists
  > Re-organize middleware test
  > Add dropsonde autowire to logging middleware

* Add receptor job and package
* Add receptor to cell in jobs.yml

Signed-off-by: Max Brunsfeld <mbrunsfeld@pivotal.io>