Removes oraclejdk8, as it's also no longer supported on th default

verhagen · verhagen · commit 5ac87fe3f54b · 2021-01-07T12:42:29.000+01:00
distribution.
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,5 @@
 language: java
 jdk:
-- oraclejdk8
 - openjdk8
 - openjdk11
 env:
