Travis CI setup for Tendrl/documentation repository is broken

[mbukatov]

Travis CI setup for Tendrl/documentation repository is broken so that checks run for every pull requests are failed. Based on the work flow drafted by @r0h4n (every repository of Tendrl group should have Travis CI configured, without any exception), we would need to fix the travis setup for this repo. I guess that it would mean running asciidoctor during the check.

[r0h4n]

@mbukatov can you verify this by sending a PR