ADD paginate for builds api

app/helpers/ci/builds_helper.rb

@@ -1,10 +1,12 @@
 module Ci::BuildsHelper
   def format_utc_time(unix_time)
     Rails.logger.info "00000000000000 #{unix_time}"
+    return nil if unix_time.blank?
     DateTime.strptime(unix_time.to_s,'%s').strftime("%Y-%m-%d %H:%M")
   end
 
   def render_duartion_time(end_time, start_time)
-    (end_time - start_time) / 10000
+    return nil if end_time == 0
+    game_spend_time(end_time - start_time)
   end
 end