revise error message for keystone.token.persistence pkg

Change-Id: Id048817a14bf5fc48e2506ab7810ca0de4ae6f27
Remove token persistence proxy

Remove the persistence backend proxy classes that were provided
for compatibility in the Juno release.

Change-Id: I5c4541136089bdf9e386ffdd859388e4b877188a
bp: removed-as-of-kilo
Updated from global requirements

Change-Id: Ia67433f2b10fe4c940f4842cd3ba7ff01bc9d9f1
Adds IPv6 url validation support

Fixes an issue where url validation fails when attempting to
create an endpoint with an IPv6 address in the URL.

Change-Id: I179b0cb7e5546a3a051e5a1e6390385a833b9f96
Closes-Bug: 1386376
Merge "Remove token persistence proxy"
Merge "revise error message for keystone.token.persistence pkg"
Merge "Updated from global requirements"