Add get_metrics command to n2vc_juju_conn and libjuju

Change-Id: I6cde1528579c8ca7aa72d935c5e570004468bb1a
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/n2vc/n2vc_juju_conn.py b/n2vc/n2vc_juju_conn.py
index fff78c9..0522028 100644
--- a/n2vc/n2vc_juju_conn.py
+++ b/n2vc/n2vc_juju_conn.py
@@ -655,6 +655,9 @@
         # return public key if exists
         return output["pubkey"] if "pubkey" in output else output
 
+    async def get_metrics(self, model_name: str, application_name: str) -> dict:
+        return await self.libjuju.get_metrics(model_name, application_name)
+
     async def add_relation(
         self, ee_id_1: str, ee_id_2: str, endpoint_1: str, endpoint_2: str
     ):