Spinnaker Release 1.7.3

Repository Signing Key

The key used to sign the spinnaker-releases Bintray repository metadata expired on May 1st, 2018 and has been rotated. If you experience errors/warnings about untrusted signatures when running apt-get or halyard, you may need to download the new public key. The new public key is available at https://bintray.com/spinnaker-releases, and can be configured by running curl https://bintray.com/user/downloadSubjectPublicKey?username=spinnaker-releases | sudo apt-key add -. The key fingerprint is 539E 3508 D31C 9E80 EF16 70C6 0440 13D2 D6BA FCDF.