Create a new client.

Client is a record of a single customer of your business. Create one for each of your clients; you will be able to issue invoices/subscriptions for them later easily using /billing_templates/ API.

Each BillingTemplateClient (there can be many attached to a single BillingTemplate) will bind a single Client to a BillingTemplate.

Either an email or (bank_account and bank_code) are requied and considered a GUID.