Add FileUploadIntegrationTest to test FileUpload hook

The FixturesFileProvider provides a dummy file to be uploaded
using the LocalFileUpload helper to verify that annotations are created
by the FileUpload hook.

Change-Id: Ie888d1f456909976cb48db2731db53d5eb2ec620
Merge pull request #585 from SemanticMediaWiki/test-fileupload

Add FileUploadIntegrationTest to test FileUpload hook