firs test (`load_balancing`) executed. Now works only with Master/Slave, most important limitation is only production Maxscale versions are available for Docker. Custom container build should be added to BuildBot

too much changes in maxscale-system-test:

• test starts from prepare_servers() which is not needed for Docker
• tests use a lot of Maxscale and backend restarts which means container restarts (and IP changes) for Docker
• copying configuartion files (maxscale.cnf, rules for fwf etc) means changing Docker image
• firt test run logic have to be changed completelly: for VM it runs mysql_install_db, creates user, but in case of Docker MariaDB server is already configured