[openstack_cpi] Look up for Retry-After on response headers
[openstack_cpi] Better message when OpenStack API returns a Bad Request
[director] Fix typo in snapshot manager [fixes #51324957]
[director] Director scheduled jobs can be optional [fixes #51775113]
Merge pull request #300 from cloudfoundry/scheduler

[director] Director scheduled jobs can be optional [fixes #51775113]
[Finishes #51595443] Snapshots are skipped when the CPI does not support snapshots
Merge pull request #299 from cloudfoundry/fix_typo

[director] Fix typo in snapshot manager [fixes #51324957]
Merge pull request #289 from cloudfoundry/retryAfter

[openstack_cpi] Improve dealing with some OpenStack API errors