Update CHANGELOG

CHANGELOG.md

@@ -39,6 +39,8 @@ IMPROVEMENTS:
     error information that caused a non-zero exit status. [GH-2999]
   - command/destroy: confirmation will re-ask question if bad input. [GH-3027]
   - guests/solaris: More accurate Solaris >= 11, < 11 detection. [GH-2824]
+  - provisioners/ansible: Generates a single inventory file, rather than
+    one per machine. See docs for more info. [GH-2991]
   - provisioners/chef-solo: New config `synced_folder_type` replaces the
     `nfs` option. This can be used to set the synced folders the provisioner
     needs to any type. [GH-2709]