Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  a2ea06a655d55d7ff783f790241e43f8149853d5

QA: Fixed Selenium tests that fail at Cloudbees

Paired with Chris McMahon.

Removed unused config.yml file and sauce_browser method. Updated to the
latest version of mediawiki_selenium Ruby gem.

Change-Id: If60c0193538f0eda3c0e5b946918c2ed9d49fa75