Add test to ensure insert is undoable. This is covered by the documentation test for undo, but I'd rather have an explicit test here, since it targets the insert method's correct use of the insert operation.
Add test to ensure insert is undoable.
This is covered by the documentation test for undo, but I'd rather have
an explicit test here, since it targets the insert method's correct use
of the insert operation.

jmacdonald/scribe