Update registration, transfer, renewal response payload

[weppos]

The response of the register, transfer and renew commands was changed (to support async tasks). All the clients must be updated, and the developer referenced updated accordingly.

Docs

• developer reference

Clients

• Elixir (Update registration, transfer, renewal response payload dnsimple-elixir#88)
• Go (Update registration, transfer, renewal responses dnsimple-go#52)
• Node
• Ruby (Update registration, transfer, renewal responses dnsimple-ruby#140)

[weppos]

@aeden is dealing with it as part of #112