[CollectionsHubsNav] Attach separator to CollectionsHubNav
[CollectionsHubsNav] Attach separator to CollectionsHubNav

artsy/reaction,artsy/reaction-force,xtina-starr/reaction,artsy/reaction-force,xtina-starr/reaction,artsy/reaction,xtina-starr/reaction,artsy/reaction,xtina-starr/reaction