Updated mediawiki/extensions
Project: mediawiki/extensions/Math  c869831f45861f36cc2e6a9ef533337a4e7c3e2e

Add and register PHP unit tests for MathSource class

This change adds test cases for the MathSource class and registers a
hook for loading these tests. Also adds documentation about how to run
these tests in README.

Change-Id: Ie58a273326e0353dfa4437b3de21a2393adb5a87