fixes https://github.com/TryGhost/Team/issues/2238
**Issue**
When viewing the 'conversions' tab on the analytics page, you could
sometimes see more listed events than the total number of conversions.
This is because other subscription events are also shown in the list.
E.g., if a new member became a paid subscriber that is attributed to a
given post, and later that subscrption has been canceled, that canceled
event would also be shown on the analytics page. This isn't really
desirable.
**Fix**
Now only 'created' subscription events are shown when the activity feed
is filtered by post_id. The other subtypes aren't related to that given
post and should be excluded.
f0b87216f7