Pin rabbitmq to 3.5.5

Pin rabbitmq to 3.5.5 for RPM platforms.  This version is the latest
and sparkly with lots of bug fixes.  Tested multi-node HA and everything
seems solid in comparison to the 3.3.z releases used previously.

backport: liberty

Change-Id: I53bf70175fd12ded132141aa499c73919a932cdf
Closes-Bug: #1503280

docker/rabbitmq/Dockerfile.j2

@@ -5,7 +5,7 @@ MAINTAINER Kolla Project (https://launchpad.net/kolla)
 
 RUN yum -y install \
         hostname \
-        rabbitmq-server \
+        https://github.com/rabbitmq/rabbitmq-server/releases/download/rabbitmq_v3_5_5/rabbitmq-server-3.5.5-3.noarch.rpm \
     && yum clean all \
     && rm -rf /var/lib/rabbitmq/*
 
@@ -17,7 +17,11 @@ RUN apt-get install -y --no-install-recommends rabbitmq-server \
 
 {% endif %}
 
-RUN /usr/lib/rabbitmq/bin/rabbitmq-plugins enable rabbitmq_management
+# NOTE(sdake): the /bin/true unblocks th rabbitmq-plugins tool. Not sure how
+#              or why.  My suspicion is it sends a signal to the parent
+#              process.
+RUN /usr/lib/rabbitmq/bin/rabbitmq-plugins enable --offline rabbitmq_management \
+    && /bin/true
 
 COPY extend_start.sh /usr/local/bin/kolla_extend_start
 RUN chmod 755 /usr/local/bin/kolla_extend_start