Add oslo.messaging to requirements

Change-Id: Id361a254b708005faada557a4d929560e5d5b791
diff --git a/requirements.txt b/requirements.txt
index 098082e..0ca9082 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,6 +5,7 @@
 keystoneauth1>=3.2.0 # Apache-2.0
 oslo.config>=4.6.0 # Apache-2.0
 oslo.log>=3.30.0 # Apache-2.0
+oslo.messaging>=5.29.0 # Apache-2.0
 paramiko>=2.0.0 # LGPLv2.1+
 python-cinderclient>=3.2.0 # Apache-2.0
 gnocchiclient>=3.3.1 # Apache-2.0