post https://api.pushologies.com/v1/segment/csv
Receive a presigned URL to which you can upload a CSV file of customerIds to create a new segment. The CSV file should be single column, unquoted, and contain only customerIds. The segment will be created with the name and description provided in the request body. The processingId returned can be used to check the status of the import. The processingId is NOT the segmentId.