Fix CI

Author: remram44

.travis.yml

@@ -4,8 +4,7 @@ python:
   - "2.7"
 install: |
   sudo apt-get update && \
-  sudo apt-get install oracle-java8-installer && \
-  sudo update-java-alternatives -s java-8-oracle && \
+  sudo apt-get install default-jre-headless && \
   pip install html5validator
 script:
   - html5validator --show-warnings