Fixes#73
Now the latest version of PlantUML is downloaded as part of the CI script. This has two consequences:
we always test against the latest and greatest PlantUML version.
PlantUML evolves at a much higher pace than plantuml-mode. This allows for some sanity check of our code with the upstream project.
builds are not reproducible
As a side effect of always downloading a (potentially) new PlantUML version, re-running the build for an old commit can lead to different outcomes. This is usually a big no-no but given the limited efforts currently spent on plantuml-mode I find it more convenient to immediately raise a flag if a new version of PlantUML causes issues.
Carlo Sciolla