def set_primary_site(id, site)
      payload = { 'site_id' => site }.to_json
      current_path = "/api/v1/collections/#{id}/set-primary"
      @conn.post(current_path, payload)
    end
def set_primary_site(id, site)
      payload = { 'site_id' => site }.to_json
      current_path = "/api/v1/collections/#{id}/set-primary"
      @conn.post(current_path, payload)
    end
sets a site to be a primary site in a site collection
 @param [int] id of the collection where the primary site is being changed
 @param [int] site nid to become the primary site
 @return [Hash{ "id" => Integer,
                "name" => String,
                "time" => "2016-10-28T09:25:26+00:00",
                "primary_site_id": Integer,
                "switched" => Boolean,
                "message" => String }]