provide mongodb dependency

#!/bin/sh
export OONI_BRIDGE_DB_FILE=/home/art/ooni-pipeline/private/bridge_db.json
export OONI_RAW_DIR=/data/pipeline/raw/
export OONI_SANITISED_DIR=/data/pipeline/sanitised/
export OONI_ARCHIVE_DIR=/data/pipeline/archive/
export OONI_PUBLIC_DIR=/data/pipeline/public/
export OONI_DB_IP="172.17.1.174"
export OONI_DB_PORT=27017
export OONI_REMOTE_SERVERS_FILE=/data/pipeline/remote_servers.txt