Update api.yaml
Update api.yaml

Update the API documentation to reflect the latest change to the ordercompletion
API call.

hoffmabc/openbazaar-go,cpacia/openbazaar-go,JustinDrake/openbazaar-go,jackkleeman/openbazaar-go,duomarket/openbazaar-test-nodes,yurizhykin/openbazaar-go,yurizhykin/openbazaar-go,OpenBazaar/openbazaar-go,JustinDrake/openbazaar-go,duomarket/openbazaar-test-nodes,cpacia/openbazaar-go,gubatron/openbazaar-go,yurizhykin/openbazaar-go,hoffmabc/openbazaar-go,jackkleeman/openbazaar-go,jackkleeman/openbazaar-go,JustinDrake/openbazaar-go,gubatron/openbazaar-go,gubatron/openbazaar-go,OpenBazaar/openbazaar-go,OpenBazaar/openbazaar-go,hoffmabc/openbazaar-go,duomarket/openbazaar-test-nodes,cpacia/openbazaar-go