Function update

test/change.test.js:276–285

(next)

      }

      function update(next) {
        const model = test.model;

        model.name += 'updated';
        model.save(function(err) {
          test.revisionForModel = Change.revisionForInst(model);

          next(err);
        });
      }
    });

    it('should not change checkpoint when rev is the same', function(done) {