Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  7f1b81d2949e73ea1abe5905cfdc53345b7d7343

Cleanup WikibaseRepo tests and add covers tags

- improves code coverage reports for WikibaseRepo
- remove dependency on MediaWikiTestCase where not needed, which I think helps make tests run slightly faster.
- cleanup namespace usage
- miscellaneous cleanup

Change-Id: I519e0febeb8431d519edf3c80b92293112a1d421