[gnome-software] Release version 3.21.91

[Richard Hughes <rhughes src gnome org>]

commit dece3db94b577de215e1055e49d2df113fbda789
Author: Richard Hughes <richard hughsie com>
Date:   Wed Aug 31 11:20:01 2016 +0100

    Release version 3.21.91

 data/appdata/org.gnome.Software.appdata.xml.in |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/data/appdata/org.gnome.Software.appdata.xml.in b/data/appdata/org.gnome.Software.appdata.xml.in
index 489b21d..2f3a2f7 100644
--- a/data/appdata/org.gnome.Software.appdata.xml.in
+++ b/data/appdata/org.gnome.Software.appdata.xml.in
@@ -46,6 +46,27 @@
    Validate with `appstream-util validate *.appdata.xml`
   -->
   <releases>
+    <release date="2016-08-31" version="3.21.91">
+      <description>
+        <p>
+          This is an unstable release in the 3.21 development series,
+          with the following improvements:
+        </p>
+        <ul>
+          <li>Add functionality to enable non-free sources</li>
+          <li>Show the device bootloader screenshot when required</li>
+        </ul>
+        <p>The following bugs are also fixed:</p>
+        <ul>
+          <li>Always return consistent results by allowing plugins to share a cache</li>
+          <li>Ensure the search text is showing when going back to search results</li>
+          <li>Only enable the firmware 'Install' button when the device is in the right mode</li>
+          <li>Remove an app from the installed view when it's uninstalled</li>
+          <li>Show percentage progress when installing firmware</li>
+        </ul>
+        <p>This release also updates translations for many languages.</p>
+      </description>
+    </release>
     <release date="2016-08-15" version="3.21.90">
       <description>
         <p>