Prepare release 5.6.0 [skip ci]

CHANGELOG

@@ -1,3 +1,6 @@
+Version 5.6.0 - 2020-05-04
+* Bug fixes (see mercurial logs for details)
+
 Version 5.4.0 - 2019-11-04
 * Bug fixes (see mercurial logs for details)
 

COPYRIGHT

@@ -1,4 +1,4 @@
-Copyright (C) 2017-2019 Cédric Krier
+Copyright (C) 2017-2020 Cédric Krier
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by

tryton.cfg

@@ -1,5 +1,5 @@
 [tryton]
-version=5.5.0
+version=5.6.0
 depends:
     ir
     stock