Use Tempest-lib's compute baremetal_nodes_client

Compute baremetal_nodes_client has been migrated to tempest-lib-
I528505bdd0a51cf720578dc6c5ef4301b72b5ce0

Now Tempest-lib provides this client as stable interface so Tempest
should start using this from lib and remove its own copy.
Also remove other files for this client like response schema, unit tests.

This commits makes Tempest to use compute baremetal_nodes_client
from Tempest-lib.

Change-Id: I2bcfcb9df21d3dfa3c0f511f46006032c0ea632b
diff --git a/tempest/clients.py b/tempest/clients.py
index c545f94..9cdc0a5 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -20,6 +20,8 @@
 from tempest_lib.services.compute.aggregates_client import AggregatesClient
 from tempest_lib.services.compute.availability_zone_client import \
     AvailabilityZoneClient
+from tempest_lib.services.compute.baremetal_nodes_client import \
+    BaremetalNodesClient
 from tempest_lib.services.identity.v2.token_client import TokenClient
 from tempest_lib.services.identity.v3.token_client import V3TokenClient
 
@@ -31,8 +33,6 @@
 from tempest.services.baremetal.v1.json.baremetal_client import \
     BaremetalClient
 from tempest.services import botoclients
-from tempest.services.compute.json.baremetal_nodes_client import \
-    BaremetalNodesClient
 from tempest.services.compute.json.certificates_client import \
     CertificatesClient
 from tempest.services.compute.json.extensions_client import \