Start jetty 9 in travis.yml file

java -jar jetty-distribution-9.4.28.v20200408/start.jar --add-to-startd=http,deploy jetty.port=8080

java -jar jetty-distribution-9.4.28.v20200408/start.jar jetty.port=8080 &

after above command
terminal will stop and can not run next command

Imprint