Reduce the 15 second container startup to 5 seconds

15 seconds seems to be overkill, whereas 5 seconds seems more
reasonable

docker/Dockerfile

@@ -97,7 +97,7 @@ RUN echo "echo 127.0.0.1 docker-dev.dbhub.io docker-dev >> /etc/hosts" >> /usr/l
     echo "/opt/rabbitmq/sbin/rabbitmq-server &" >> /usr/local/bin/start.sh && \
     echo "" >> /usr/local/bin/start.sh && \
     echo "# Wait for RabbitMQ to start before launching the DBHub.io daemons" >> /usr/local/bin/start.sh && \
-    echo "sleep 15" >> /usr/local/bin/start.sh && \
+    echo "sleep 5" >> /usr/local/bin/start.sh && \
     echo "" >> /usr/local/bin/start.sh && \
     echo "su - dbhub -c 'if [ -f "${DBHUB_SOURCE}/.env" ]; then source ${DBHUB_SOURCE}/.env; fi; CONFIG_FILE=${CONFIG_FILE} /usr/local/bin/dbhub-webui >>/home/dbhub/output.log 2>&1 &'" >> /usr/local/bin/start.sh && \
     echo "su - dbhub -c 'if [ -f "${DBHUB_SOURCE}/.env" ]; then source ${DBHUB_SOURCE}/.env; fi; CONFIG_FILE=${CONFIG_FILE} /usr/local/bin/dbhub-api >>/home/dbhub/output.log 2>&1 &'" >> /usr/local/bin/start.sh && \