add constraint for turn_scorings, and use upsert

[avimoondra]

Need to clear these out first, otherwise migration will fail in prod...

with counts as (select turn_id, card_id, count(1) as count from turn_scorings group by turn_id, card_id)
select * from counts where count > 1;

[avimoondra]

Analyze turn scorings, and if it's reliable to use for end game stats

[avimoondra]

related to #77

[avimoondra]

with counts as (select turn_id, card_id, count(1) as count from turn_scorings group by turn_id, card_id)
select count(1) from counts where count > 1;

as of wed may 20, 10:46am PST - 609

[avimoondra]

Clean out bad started_review_at data