Travis: Allow Java EA builds to fail.
diff --git a/.travis.yml b/.travis.yml
index 9811140..1e3de86 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,6 +22,10 @@
   - openjdk13
   - openjdk-ea
 
+matrix:
+  allow_failures:
+    - jdk: openjdk-ea
+
 script:
   - mvn