Shows the migrated message + specs
Adds dashboard to the window var
Adds email to migrated message
Fixes copy (we're showing the updated_at not the created_at date)
Adds new spec to the sortable class
Merge branch 'develop' of github.com:CartoDB/cartodb20 into develop

* 'develop' of github.com:CartoDB/cartodb20:
  fixes vizzuality/cartodb-management#2500
  return created at in visualization presenter
  Add importer spec for populated places sample dataset
  changed padding to round buttons - fixes vizzuality/management#2514
Merge branch 'develop' of github.com:CartoDB/cartodb20 into develop

* 'develop' of github.com:CartoDB/cartodb20:
  fixes vizzuality/cartodb-management#2517