This migrates the above files from tempest. This includes tempest commits:
* baremetal_nodes_client.py : I93a0e82063900ffd1893e63a992f9f827c5b5ae2
* test_baremetal_nodes_client.py: I3ad6761651cec5e66012d08e6b63322f53286a5c
* v2_1/baremetal_nodes.py : Ica929c402a3d042ae751302384e68853eb28b405
to see the commit history for these files refer to the above sha1s in the tempest repository
Partially implements blueprint migrate-service-clients-to-tempest-lib
Change-Id: I528505bdd0a51cf720578dc6c5ef4301b72b5ce0