Removed require relative and replaced with ordinary require.

lib/apex.rb

-require_relative 'kiss/kiss_serial'
-require_relative 'aprs/aprs_kiss'
+require 'kiss/kiss_serial'
+require 'aprs/aprs_kiss'
 
 module Apex
     VERSION = "0.0.1"

lib/aprs/aprs_kiss.rb

-require_relative '../kiss/constants'
+require 'kiss/constants'
 
 module Aprs
     class AprsKiss

lib/kiss/kiss_abstract.rb

 require 'thread'
 require 'abstraction'
-require_relative 'constants'
+require 'kiss/constants'
 
 module Kiss
     class KissAbstract

lib/kiss/kiss_serial.rb

 require 'serialport'
-require_relative 'kiss_abstract'
+require 'kiss/kiss_abstract'
 
 module Kiss
     class KissSerial < KissAbstract