Store model in DB so that we can add points asynchronously when the model is destroyed

Failing unit test for BaseTargetFinder

Add a column to the merit_actions table

Store target object in actions table

BaseTargetFinder uses the stored data

Move test to correct part of file

Typo in points rule

Test that the action can be saved with a serialised model

Add serialisation for the target_data field.

Get target from serialised data correctly

Add field for mongoid

Add assertion to action test

Make YAML serialisation explicit