Add Openstack Swift API Support

[Xuanwo]

https://docs.openstack.org/api-ref/object-store/

Developers can run tests using https://hub.docker.com/r/openstackswift/saio

[morristai]

Sure, I will take a look into this implementation.

[Xuanwo]

Openstack Swift API support has been added, let's add it's behavior test!