Create the Profile.follow() method

calsocial/models.py

@@ -317,6 +317,23 @@ class Profile(db.Model):  # pylint: disable=too-few-public-methods
 
         return NotImplemented
 
+    def follow(self, follower):
+        """Make ``follower`` follow this profile
+        """
+
+        if not isinstance(follower, Profile):
+            raise TypeError('Folloer must be a Profile object')
+
+        user_follow = UserFollow(follower=follower, followed=self, accepted_at=datetime.utcnow())
+        db.session.add(user_follow)
+        notification = Notification(profile=self,
+                                    actor=follower,
+                                    item=self,
+                                    action=NotificationAction.follow)
+        db.session.add(notification)
+
+        return user_follow
+
 
 class Event(db.Model):
     """Database model for events