[gtksourceview] Release 3.21.6

[Sébastien Wilmet <swilmet src gnome org>]

commit e2ea5c69f0d2c1ee649b5b913e20b66844e313b3
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Sep 10 12:23:03 2016 +0200

    Release 3.21.6

 NEWS |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index d4a67ea..7e4c80b 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+News in 3.21.6
+--------------
+* Improvements to the syntax highlighting of: CSS and Rust
+* Translation updates
+
 News in 3.21.5
 --------------
 * Fix an infinite loop in whitespace drawing