Specify 'trusty' on dist explicitly

kazuki43zoo · kazuki43zoo · commit 6d818e47fa6c · 2019-07-02T00:01:28.000+09:00
Fixes gh-61
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,8 @@
 language: java
 
+# workaround build error using oraclejdk8 on xenial
+dist: trusty
+
 jdk:
   - openjdk11
   - oraclejdk8
