add validation for generating CSV
add validation for generating CSV

mrpau/kolibri,learningequality/kolibri,learningequality/kolibri,learningequality/kolibri,indirectlylit/kolibri,mrpau/kolibri,learningequality/kolibri,indirectlylit/kolibri,mrpau/kolibri,indirectlylit/kolibri,indirectlylit/kolibri,mrpau/kolibri