Test matrix: exclude Java 9, Java 10, Java 12 from CI

[vlsi]

LTS releases are 8, 11, so it makes no sense to test with Java 9, 10, and 12.

It probably makes sense to test with Java 8, 11, 13, +ea (however, the current Gradle does not support Java 14-ea yet)

[bokken]

+1

…

On Thu, Mar 5, 2020 at 8:13 AM Vladimir Sitnikov ***@***.***> wrote: LTS releases are 8, 11, so it makes no sense to test with Java 9, 10, and 12. It probably makes sense to test with Java 8, 11, 13, +ea (however, the current Gradle does not support Java 14-ea yet) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1727?email_source=notifications&email_token=AAW3U3PJHUE47SLMTY5LYNTRF6XR5A5CNFSM4LCK2SL2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4ISZMHHA>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAW3U3MIUDJFREMWVOPD5CTRF6XR5ANCNFSM4LCK2SLQ> .