use python 3.5 instead of 3.4 when uploading artifacts
use python 3.5 instead of 3.4 when uploading artifacts

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