publish gem version 4.0.3

- better tests for noop mode
- noop for rake middleware
- updated rdoc comments in appoptics_apm/api. Documentation
  for the methods in this folder can be generated with rdoc.

Author: prettycoder

lib/appoptics_apm/version.rb

@@ -8,7 +8,7 @@ module AppOpticsAPM
   module Version
     MAJOR = 4
     MINOR = 0
-    PATCH = 2
+    PATCH = 3
 
     STRING = [MAJOR, MINOR, PATCH].compact.join('.')
   end