Merge branch '3410552-fix-tests' into '8.x-3.x'

composer.json

config/schema/ds.entity_display.schema.yml

config/schema/ds.field.schema.yml

config/schema/ds.field_template.schema.yml

config/schema/ds.schema.yml

config/schema/ds.views.schema.yml

css/ds-2col-fluid.css

css/ds-2col-stacked-fluid.css

css/ds-3col-equal-width.css

css/ds-3col-stacked-equal-width.css

css/ds-3col-stacked-fluid.css

css/ds-3col-stacked.css

css/ds-3col.css

css/ds-4col.css

css/ds.admin.css

ds.info.yml

ds.module

includes/field_ui.inc

js/ds.admin.js

modules/ds_extras/config/schema/ds_extras.schema.yml