Git commits in Moodle 3.5.6 by sam marshall

commit 22baf5c0aa3f43ec419f9bed6c794d3a3279c9d6
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Thu, 18 Apr 2019 22:04:15 +0800
Tag:    v3.5.6

MDL-65375 Restore: Null data in other field should be serialised

commit 0ec20a18a45cc08b01ff704402917bb839ff2973
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Fri, 01 Mar 2019 01:36:30 +0800
Tag:    v3.5.6

MDL-64979 Behat: Add option to increase timeouts