add ci jobs for java 8, 11 and 13
This MR adds the necessary CI jobs to build against java 8, 11 and 13.
Please note that this only adds jobs.
They will fail until !2 (merged) is merged.
Closes #4
This MR adds the necessary CI jobs to build against java 8, 11 and 13.
Please note that this only adds jobs.
They will fail until !2 (merged) is merged.
Closes #4