Implement GET /keypair in Go Client Library

[davidraker]

Generate a new public/private keypair.

Request:

• Authorization: BEARER <jwt_token>

Response:

• With valid BEARER token on success: 200 OK
  • Content Type: application/json
  • Body:

    {
        "public": "<public_key>,
        "private": "<private_key>
    }
    

• With valid BEARER token on failure: 400 Bad Request
  • Content Type: application/json
  • Body:

    {
        "error": "<Error Message>"
    }
    

• With invalid BEARER token: 401 Unauthorized