Add application_credential params to Storage class

[jochenehret]

• Swift supports application credentials: https://github.com/restic/restic/pull/2156
• see also https://github.com/fog/fog-openstack/pull/533

[geemus]

Do you need a release with this?

[jochenehret]

Yes, a release would be great! Then we can integrate it into https://github.com/cloudfoundry/cloud_controller_ng/blob/main/Gemfile Thanks for your quick support!

[geemus]

Sorry for the delay, kept not quite finding the time, I just released this in v1.1.3.