Start v6
Migrate
Update lint
Fix validation errors
Migrate min/maxzooms
Migrate render ⇢ layout, style ⇢ paint

https://github.com/mapbox/mapbox-gl-style-spec/issues/166
Single text positioning property

https://github.com/mapbox/mapbox-gl-style-spec/issues/197
Merge branch 'v6' into mb-pages