WIP - Switch Travis-CI to test java EA builds

[mmoayyed]

Experiment with Travis CI building CAS using Java EA builds.

• Blocked by JDK 14/15 compatibility google/error-prone#1106

[stale]

This patch has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[CLAassistant]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ mmoayyed
❌ apereocas-bot
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[stale]

This patch has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This patch has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.