[atlas] Minor change in the API Participation Requests endpoint

Dear Atlas users, We're planning to roll-out a minor change in the API Participation Requests endpoint. We'll be changing the response that gets sent out when a Participation Request is submitted. Although minor, the change may break your code if you are making use of the response. Current response example: [35878] Future response example after roll-out: { 'request_ids': [35878] } We plan to put this change into production two weeks from now. For those who don't know what Participation Requests are, they allow you to add or remove probes from a pre-existing measurement. You can find more information in https://atlas.ripe.net/docs/api/v2/manual/participation_requests.html Regards — Agustín Formoso RIPE NCC