Remove calls to InputSuppliers.of

API removed in be1da2501ec805c5f08b711a1245c2505ca7eb56.
Merge pull request #21 from maginatics/remove-input-suppliers-of

Remove calls to InputSuppliers.of
Domain API for Rackspace Cloud DNS.
Merge pull request #20 from rackerlabs/rax-dns-domains

Domain API for Rackspace Cloud DNS.