[gnome-software] featured: provide some attribution

[Jakub Steiner <jimmac src gnome org>]

commit 4fa50283f85df70784075fa7fa493ef82d7e744f
Author: Jakub Steiner <jimmac gmail com>
Date:   Tue Feb 9 11:00:48 2016 +0100

    featured: provide some attribution
    
    - forgot to add credits to the image

 AUTHORS |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/AUTHORS b/AUTHORS
index e278790..611cba1 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1,3 +1,6 @@
 Richard Hughes <richard hughsie com>
 Matthias Clasen <mclasen redhat com>
 Kalev Lember <kalevlember gmail com>
+
+Backdrop image for Builder featured banner used with permission by
+Adam Wyles -- http://www.flickr.com/photos/the-travelling-bum/6336397663/