Checks a participant in, setting checked_in_at to the current time.
POST
https://api.challonge.com/v1/tournaments/{tournament}/participants/{participant_id}/check_in.{json|xml}
| Name | Description | 
|---|---|
| Benodigd api_key | Your API key (required unless you're using HTTP basic authentication) | 
| Benodigd {tournament} (in URL string) | Tournament ID (e.g. 10230) or URL (e.g. 'single_elim' for challonge.com/single_elim). If assigned to a subdomain, URL format must be :subdomain-:tournament_url(e.g. 'test-mytourney' for test.challonge.com/mytourney) | 
| Benodigd {participant_id} (in URL string) | The participant's unique ID |