Add credential generation for manager personas

Prepares credentials for domain manager and project manager personas,
required for RBAC tests in Keystone.

Related-Bug: https://review.opendev.org/c/openstack/keystone/+/924132
Change-Id: I2d133326eddb3cf70e2bb1711d8e20f4514f8fca
diff --git a/releasenotes/notes/add-manager-creds-49acd9192110c3e3.yaml b/releasenotes/notes/add-manager-creds-49acd9192110c3e3.yaml
new file mode 100644
index 0000000..a5d7984
--- /dev/null
+++ b/releasenotes/notes/add-manager-creds-49acd9192110c3e3.yaml
@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Add support for project manager and domain manager personas by adding
+    ``get_project_manager_creds`` and ``get_domain_manager_creds`` to
+    the ``DynamicCredentialProvider`` and ``PreProvisionedCredentialProvider``
+    classes of the common library.