Identity v2 has undocumented support for token delete and
keystoneclient also has support.
Change-Id: Ib98d17958ceb88f7b63471691dee71fdb884ce2e
Closes-Bug: #1318442
Implements token create subcommand which is an equivalent of keystone
token-get command. Original "wrap" parameter for keystone token-get is
not implemented yet due to cliff Bug #1269299
This is a part of: blueprint add-identity-token-support
Change-Id: I9e4de93306f2f5959717b5219621da03961524d8