* Only retain last 14 builds.
* Fix user.home on Docker builds
* Interact with `new-issue-branch` script properly by using `SNAPSHOT` as suffix for snapshot builds.
Now that Spring HATEAOS is based on Spring Framework 5.2.0.M3, which has upgraded it's handling of charset variables in web responses, we can go back to also testing against Spring Framework 5.2.0.BUILD-SNAPSHOT.