New features/modifications:
- API instance SMTPApi renamed to TransactionalEmailsApi
- Added Contact Id as additional key for contact operations
- Extended statistics for A/B test results
- Added sender id parameter in sendTransactionalEmail
- Made IP non-mandatory for getContactDetails route
- RedirectionUrl is now mandatory for DOI
- Sent event now included in events array for transactional webhook
- Change in length of sender
- Fixed response for getEmailCampaigns in case of no email campaign
- Removed parameters - Subject, contentType, bcc, and cc from sendReport routes (will be ignored if passed in the request)