Properly track required relations

Add missing `juju-info` interface to squelch charm log
messages.

src/layer.yaml

@@ -1,5 +1,6 @@
 includes:
   - layer:openstack
+  - interface:juju-info
   - interface:vault-kv
   - interface:barbican-secrets
 options:

src/lib/charm/openstack/barbican_vault.py

@@ -23,6 +23,7 @@ class BarbicanVaultCharm(charms_openstack.charm.OpenStackCharm):
     name = 'barbican-vault'
     packages = ['python3-castellan']
     python_version = 3
+    required_relations = ['secrets-storage']
     adapters_class = charms_openstack.adapters.OpenStackRelationAdapters
 
     _installed_ca_name = None

src/reactive/barbican_vault_handlers.py

@@ -41,7 +41,7 @@ def secret_backend_vault_request():
     with charm.provide_charm_instance() as barbican_vault_charm:
         secrets_storage.request_secret_backend(
             barbican_vault_charm.secret_backend_name, isolated=False)
-    reactive.clear_flag('secrets-storage.connected')
+        barbican_vault_charm.assess_status()
 
 
 @reactive.when_all('endpoint.secrets.joined', 'secrets-storage.available',