Added entry for RubyGems 3.0.1 to NEWS.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66527 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -529,10 +529,12 @@ sufficient information, see the ChangeLog file or Redmine
 
 [RubyGems]
 
-  * Upgrade to RubyGems 3.0.0
+  * Upgrade to RubyGems 3.0.1
 
   * https://blog.rubygems.org/2018/12/19/3.0.0-released.html
 
+  * https://blog.rubygems.org/2018/12/23/3.0.1-released.html
+
 [Set]
 
   [Aliased methods]