Trigger ruby yard doc for our gems

Generate documentation for mediawiki/selenium and mediawiki/ruby/api
under https://doc.wikimedia.org/rubygems/ :-)

Jenkins jobs added by:
https://gerrit.wikimedia.org/r/#/c/160983/

Change-Id: I10edcf23eec7453c73c2b4e43b2bc6aeb637bafb