Migrates travis.yml from legacy to container-based infrastructure

Author: lucor

.travis.yml

@@ -8,4 +8,5 @@ before_script:
   - sh -e /etc/init.d/xvfb start
   - sleep 1
 script:
-  - ./node_modules/.bin/gulp test-all-versions
+  - ./node_modules/.bin/gulp test-all-versions
+sudo: false