Add Subscription
POST https://api.vivapayments.com/dataservices/v1/webhooks/subscriptions
Request Body
{"url"=>"https://www.merchantwebsite.com/webhooks/receive", "secret"=>"TestSecretKeyForHMAC", "events"=>["SaleTransactionsFileGenerated"]}
POST https://api.vivapayments.com/dataservices/v1/webhooks/subscriptions
{"url"=>"https://www.merchantwebsite.com/webhooks/receive", "secret"=>"TestSecretKeyForHMAC", "events"=>["SaleTransactionsFileGenerated"]}