Upload to unstable.

debian/changelog

@@ -1,4 +1,4 @@
-ostree (2016.5-3) UNRELEASED; urgency=medium
+ostree (2016.5-3) unstable; urgency=medium
 
   * Remove ostree-grub2 and the boot-related parts of ostree, leaving
     the library and the command-line tool, which are also used by
@@ -6,6 +6,7 @@ ostree (2016.5-3) UNRELEASED; urgency=medium
     When we have documentation for how to use and test OSTree
     deployments with a Debian derivative (see #824649), they should be
     reinstated in an ostree-boot package (see #824650).
+  * Upload to unstable.
 
  -- Simon McVittie <smcv@debian.org>  Wed, 08 Jun 2016 11:58:01 +0100