Create a Session in Amatino Swift. This is analogous to "logging in" to the Amatino API

createSession.swift

// Amatino Swift: https://github.com/amatino-code/amatino-swift
// Double entry accounting API

try Session.create(
    email: "clever@cookie.com",
    secret: "high entropy passphrase",
    callback: { (error, session) in
        guard error == nil else {
          // Handle errors. In particular, look out for 401, which
          // would indicate invalid credentials such as a mistyped
          // passphrase.
        }
        // Store the session somewhere for use with later requests.
        print("Created new Session with ID: \(session.id)")
        return
    }
)