AT

• Create corresponding build for MySQL 5.7 / 5.6 docker images in Infrastructure Jenkins

Hint:

• [x] Increase MySQL version in Job-Dsl-Generator project (File: Database_Master.groovy)
• [x] Apply Job-DSL-Generator changes to JobDsl branches
• [x] Add the new version to https://github.com/camunda-ci/jenkins-job-dsl-seed-jobs/blob/master/jobs/infrastructure/docker_images.dsl