Update changelog.yml

Author: solnic

changelog.yml

@@ -5,7 +5,7 @@
   fixed:
   added:
   - 'You can now access current value''s index via `rule(:foo).each do |index:|` (issue
-    #657 done via #657) (@mrbongiolo)'
+    #606 done via #657) (@mrbongiolo)'
   changed:
   - "`Result#error?` is now a public API and it takes into consideration both schema
     and rule errors (issue #655 fixed via #656) (@PragTob)"