Implemetation of tempest client for keystone v3 OS_FEDERATION API

This change adds tempest client for identity_providers, protocols,
mappings and service_providers. The unit tests are also added.

Change-Id: I272a45a3f5f8bd78840d463dbcb00b8f0b0a219e
Closes-Bug: #1697429
diff --git a/releasenotes/notes/Add-keystone-v3-OS_FEDERATION-APIs-as-tempest-clients-fe9e10a0fe5f09d4.yaml b/releasenotes/notes/Add-keystone-v3-OS_FEDERATION-APIs-as-tempest-clients-fe9e10a0fe5f09d4.yaml
new file mode 100644
index 0000000..33df7c4
--- /dev/null
+++ b/releasenotes/notes/Add-keystone-v3-OS_FEDERATION-APIs-as-tempest-clients-fe9e10a0fe5f09d4.yaml
@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    The following tempest clients for keystone v3 OS_FEDERATION API were
+    implemented in this release
+
+    * identity_providers
+    * protocols
+    * mappings
+    * service_providers