updated serialized_attributes to reject nil values
updated serialized_attributes to reject nil values

kappiah/axlsx,woto/axlsx,legitscript/axlsx,VueOps/axlsx,nilbus/axlsx,mromulus/axlsx,raghavendra-prithvi/axlsx,randym/axlsx,romuloceccon/axlsx,alexanderfrankel/axlsx,sh-ft/axlsx,sr-education/axlsx,clarkcutler/axlsx,Debiancc/axlsx,pedrogarrett/axlsx,bradstewart/axlsx