.travis.yml in hydra-derivatives-3.0.0 vs .travis.yml in hydra-derivatives-3.0.1

@@ -4,9 +4,11 @@
 rvm:
   - 2.
 env:
   global:
     - NOKOGIRI_USE_SYSTEM_LIBRARIES=true
+jdk:
+  - oraclejdk8
 notifications:
   email:
     recipients:
       - "[e-mail]"
     on_success: "change"