Update Travis configuration for new html5validator

Author: remram44

.travis.yml

@@ -1,8 +1,11 @@
 language: python
-sudo: false
+sudo: required
 python:
   - "2.7"
 install:
+  - sudo apt-get update
+  - sudo apt-get install oracle-java8-installer
+  - sudo update-java-alternatives -s java-8-oracle
   - pip install html5validator
 script:
   - html5validator --show-warnings