Abort if the docker cannot be started

docker/repro

@@ -20,7 +20,7 @@ else
 fi
 
 if [ $skip_experiments == 0 ]; then
-    ./start-docker
+    ./start-docker || exit 1
     docker exec -it ${TEEMS_DOCKER_PREFIX}teems $DOCKER_ENV ./run_all_experiments.py
     docker exec -it ${TEEMS_DOCKER_PREFIX}teems ./logs_to_csv.py Experiments/ID Experiments/id-channel.csv
     docker exec -it ${TEEMS_DOCKER_PREFIX}teems ./logs_to_csv.py Experiments/Token Experiments/token-channel.csv