Our current build process can be slow due to running `apt-get update` and installing utilities (rsync). I'd like to look into whether or not we can run a slimmer docker image (possibly with rsync pre-installed) and use mvnw to pull maven on each run. So, things to look at: * openjdk docker image instead of maven * would still need to fetch rsync * mvnw usage in gitlab-ci.yml * custom docker image which we can build and provide for ourselves for testing (still using mvnw)