Remove Stormpath auth. API shutting down.
Remove Stormpath auth. API shutting down.

Per Stormpath's announcement, their API will be shutting down on
8/17/2017 at noon PST.

https://stormpath.com/oktaplusstormpath

Closes #42914

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt