Checks if a user can reclaim given reward.
Deploy with npm run deploy:{env}.
MENTIONS_TABLEthat the entries are stored inMAX_RETRIESindicates how many times do we check the DynamoDB before rejectingRETRY_DELAYhow often do we retryREDEMPTION_DELAYhow often can user redeem an offer from one promoter
If handle does not exists in mentions, we return 404.
If user has already redeemed, we return 403 with milliseconds till the request can be retried.
On unexpected server error, we return 500.
Otherwise returns 200.