Implement EZP-21169: As a Tester I want BDD running on Travis

Issue: https://jira.ez.no/browse/EZP-21169

This approach is using mysql, I attempted using sqlite first but since legacy is needed it can not work without making a new sql driver for legacy which is out of the scope of this story.

For review & testing, remaining tasks:
- [x] Support for self installing ez Publish based on fixtures ( ezsystems/ezpublish-kernel#486 )
- [x] Travis config and adjustmenst for behat test runs
- [x] New fixture dump based on more recent clean install of ezdemo with all tables so it might work on legacy (as needed by DemoBundle at the moment)
- [ ] Full ezpublish schema for mysql, postgres and sqlite so data dump can be reused for integration tests as well 
- [x] Merge https://github.com/ezsystems/ezpublish-kernel/pull/486
- [x] Enable Travis hook
- [x] Run composer update on this branch and push to trigger first test run
- [x] Get Sahi running somehow for javascript tests (pr preferably casperJS if Mink driver exists)
- [x] Add Demo Bundle tests that actually test javascript and login functionality