Create a single cohort group REST Endpoints

Designer/Randomization APIs/Randomization Cohorts/Create a single cohort group
The operations from the Designer/Randomization APIs/Randomization Cohorts/Create a single cohort group category.
V1.0
Method: post
Path: /ec-designer-svc/rest/v1.0/studies/{studyId}/versions/{version}/randomizations/{randomId}/cohorts