Added entry of Psych.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66363 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -426,6 +426,10 @@ sufficient information, see the ChangeLog file or Redmine
     * Add Net::HTTPClientException to deprecate Net::HTTPServerException,
       whose name is misleading.  [Bug #14688]
 
+[Psych]
+
+  * Upgrade Psych 3.1.0.pre2
+
 [REXML]
 
   [Improved some XPath implementations]