Add tests for encryption_key_ref

Positive test -
 1. create barbican secret and create share using secret UUID

Negative test -
 1. invalid encryption key ref
 2. invalid share type extra-spec
 3. absent encryption key ref

partially-implements: blueprint share-encryption
Depends-On: https://review.opendev.org/c/openstack/requirements/+/963685
Change-Id: I3145f9cd6847464b2920f1b0a35e6c211e45b26e
Signed-off-by: Kiran Pawar <kinpaa@gmail.com>
diff --git a/requirements.txt b/requirements.txt
index ae5ea16..d44cb74 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,6 @@
 ddt>=1.6.0 # MIT
 oslo.log>=3.36.0 # Apache-2.0
 tempest>=31.1.0 # Apache-2.0
+
+# the encryption tests require it
+barbican-tempest-plugin>=1.6.0 # Apache-2.0