Unable to create groups by non-admin thru API

Even though I can create groups in GitLab itself (as I am granted with privilege to create groups) I cannot find a way how to force API to create group with current user as owner of the group and thus chance to add projects and members through API.

In other words: POST /groups should not be admin only, as not only admin has right to create group.

But following change (mad with respect to group_controller) doesn't cut it:

lib/api/groups.rb - line 43

post do
  required_attributes! [:name, :path]

  attrs = attributes_for_keys [:name, :path]
  @group = Group.new(attrs)

  if @group.save
    @group.add_owner(current_user)
    present @group, with: Entities::Group
  else
    not_found!
  end
end

This creates group with name and path as intended, but current_user in not added to this group and whole presented result is a nil.