[CI] Use Java 8 on Travis CI
[CI] Use Java 8 on Travis CI

rvais/xmvn,fedora-java/xmvn,fedora-java/xmvn,mizdebsk/xmvn,mizdebsk/xmvn,rvais/xmvn,rvais/xmvn,fedora-java/xmvn,mizdebsk/xmvn,mizdebsk/xmvn,rvais/xmvn