Resolve "Add RabbitMQ for MessageBus triggers"

Closes #1 (closed)

\approve @ds @gislars

Dockerfile

@@ -13,7 +13,7 @@ RUN apt-get update \
     python-setuptools \
     libpq-dev; \
     done \
-    apt-get clean \
+    && apt-get clean \
     && rm -rf /var/lib/apt/lists/*
-RUN pip install pgxnclient
+RUN pip install pgxnclient \
     && pgxnclient install pg_amqp