[atk] Added contributors line on 2.15.4 entry

[Alejandro Piñeiro Iglesias <apinheiro src gnome org>]

commit d7208f2be7ebe5f5e5aaa5af4c8e1e809f73e7c8
Author: Alejandro Piñeiro <apinheiro igalia com>
Date:   Tue Jan 20 18:44:38 2015 +0100

    Added contributors line on 2.15.4 entry

 NEWS |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index 5284522..5faf399 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,9 @@ Changes in version 2.15.4:
    * Bug 742806: Add new roles for fractions, roots, subscripts, and
      superscripts
 
+Contributors:
+Joanmarie Diggs
+
 Changes in version 2.15.3:
 ==========================
 *