Allow null channel titles

Whilst we don't expect them, the API shouldn't explode if they
exist.
Merge pull request #570 from atlasapi/allow-null-titles

Allow null channel titles
Remove double semi-colon
Merge pull request #550 from atlasapi/mbst-9478-sitemap-improvements

Ingest series clips
Add in whitelisted rugby event ids
Merge pull request #571 from atlasapi/yv-equiv-tasks

Make YouView updaters consistent for all YV publishers
Temporary removing completed step for Rovi Full Ingest on stage
Merged temporary Rovi full ingest changes and fixed conflicts