Add changelog entry for #2280.

myronmarston · myronmarston · commit 9c0bff604a61 · 2016-07-06T16:52:04.000-07:00
diff --git a/Changelog.md b/Changelog.md
@@ -1,3 +1,11 @@
+### Development
+[Full Changelog](http://github.com/rspec/rspec-core/compare/v3.5.0...master)
+
+Bug Fixes:
+
+* Ensure that config hooks that are added to existing example groups are
+  added only once. (Eugene Kenny, #2280)
+
 ### 3.5.0 / 2016-07-01
 [Full Changelog](http://github.com/rspec/rspec-core/compare/v3.5.0.beta4...v3.5.0)
 
