Notification plugin is returning 'FINALIZED' instead of 'FINISHED'

The Jenkins Notification plugin has changed the phase name from FINISHED to FINALIZED, so the changes store FINALIZED into the capomastro database. Also, if the database says FINISHED for some records, it still displays FINALIZED in the UI.
fixes #94 
This (and the associated static methods) seem to be duplicating the [`choices`](https://docs.djangoproject.com/en/1.6/ref/models/fields/#choices) functionality Django provides.