Support Identity v3

[stenstad]

Hi!

Since the release of Openstack Havana the preferred version of Identity to use is v3. Some cloud providers have now migrated to only supporting v3 for token generation to get support for domains.

Currently Net::OpenStack::Compute does not work with providers that require support for Identity v3.

Would it be possible to add support for Identity v3 in this project as well?

[ironcamel]

Hi @stenstad, I don't have time right now to add that, but if you or someone else would like to submit a pull request for that I would be glad to look at it.