Update change log

Author: jim-easterbrook

CHANGELOG.txt

@@ -16,6 +16,10 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see
 <http://www.gnu.org/licenses/>.
 
+Changes in v0.17.2:
+  1/ Binary wheels incorporate libexiv2 v0.28.4.
+  2/ Fix TimeValue test when run with local negative UTC offset.
+
 Changes in v0.17.1:
   1/ Fix crash when using localised exceptions on Windows.