[libpeas] Release 1.21.0

[Christian Hergert <chergert src gnome org>]

commit 9b794ad7cc6c2fc696f549e000a912e907652c00
Author: Christian Hergert <chergert redhat com>
Date:   Mon Aug 7 16:17:45 2017 -0700

    Release 1.21.0

 NEWS |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index 58f8ad0..7f34097 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,16 @@
+Overview of Changes in libpeas 1.21.0
+====================================
+
+* Consider all an interfaces potential properties
+* Fix PeasEngine virtual annotations
+* Allow extensions to be an Abstract Base Class
+* Cache an extension type's base class and interfaces
+
+* Translation updates:
+  - Belarusian
+  - Croatian
+  - Simplified Chinese
+
 Overview of Changes in libpeas 1.20.0
 ====================================