Resolve "Add RabbitMQ for MessageBus triggers"

Closes #1 (closed)

\approve @ds @gislars

Dockerfile

@@ -10,9 +10,10 @@ RUN apt-get update \
     build-essential \
     python3-pip \
     python-dev \
-    python-setuptools; \
+    python-setuptools \
+    libpq-dev; \
     done \
-RUN pip install pgxnclient
-RUN pgxnclient install pg_amqp
-RUN apt-get clean \
+    apt-get clean \
     && rm -rf /var/lib/apt/lists/*
+RUN pip install pgxnclient
+    && pgxnclient install pg_amqp