ammend changelog for rspec#1869

[skip ci]

Author: JonRowe

Changelog.md

@@ -6,7 +6,7 @@ Enhancements:
   (Jon Rowe, #1866)
 * Make `RSpec::Core::Reporter#message` a public supported API. (Jon Rowe, #1866)
 * Allow custom formatter events to be published via
-  `RSpec::Core::Reporter#publish(hash)`. (Jon Rowe, #1869)
+  `RSpec::Core::Reporter#publish(event_name, hash_of_attributes)`. (Jon Rowe, #1869)
 
 ### 3.2.0 / 2015-02-03
 [Full Changelog](http://github.com/rspec/rspec-core/compare/v3.1.7...v3.2.0)