Bump 3.20.2 release

NEWS

+==============
+Version 3.20.2
+==============
+
+Project:
+        * Small code cleanups
+        * Fix Scheduled and Today panels' misbehavior
+
+Translations:
+        * Portuguese (Tiago Santos)
+
 ==============
 Version 3.20.1
 ==============

configure.ac

 dnl -*- mode: m4 -*-
 AC_PREREQ([2.69])
-AC_INIT([gnome-todo],[3.20.1],[https://bugzilla.gnome.org/enter_bug.cgi?product=gnome-todo],[gnome-todo])
+AC_INIT([gnome-todo],[3.20.2],[https://bugzilla.gnome.org/enter_bug.cgi?product=gnome-todo],[gnome-todo])
 
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_SRCDIR([src/main.c])