add basic Goss validation/tests, and add version validation in Dockerfile as well
add Dockerfile linting
add automated testing/deployment, as per other repos
improve automation / usability w.r.t CIRCLE-19667—users now need only add new version information in one place* in order for new versions to automatically be built, tested, and deployed
*technically 2 places still, in this case, but that's only b/c openjdk has unique per-version download URLs—other images will mostly only need 1 simple version string added in 1 place to add a new version
* technically 2 places still, in this case, but that's only b/c openjdk has unique per-version download URLs—other images will mostly only need 1 simple version string added in 1 place to add a new version