Merge branch 'release/0.3.1' into develop
Leave 'id' for Resourceful to manage.
Use 'x.key' to get the key name, rather than hard-coding to 'id'.
Use 'all()' rather than 'find({})'.
Add test for update following 'find()', rather than 'get()'.

Note that this requires an updated Resourceful.
Bump version number.
Merge branch 'release/0.4.0'