feat: Log actions when task completion status changes

server/api/models/Action.js

@@ -15,6 +15,8 @@ const Types = {
   MOVE_CARD: 'moveCard',
   ADD_MEMBER_TO_CARD: 'addMemberToCard',
   REMOVE_MEMBER_FROM_CARD: 'removeMemberFromCard',
+  COMPLETE_TASK: 'completeTask',
+  UNCOMPLETE_TASK: 'uncompleteTask',
 };
 
 const INTERNAL_NOTIFIABLE_TYPES = [Types.MOVE_CARD, Types.ADD_MEMBER_TO_CARD];