POST /orders
{
  id: 5,
  state: 'payment-expected',
  _links: {
    self: {
      method: 'GET',
      href: '/orders/5',
    }
    payment: {
      method: 'PUT',
      href: '/orders/5/payments',
    },
    change: {
      method: 'PUT',
      href: '/orders/5/changes',
    }
    cancel: {
      method: 'PUT',
      href: '/orders/5/cancels',
    }
  }
}

GET /orders/:id            // refresh


PUT /order/:id/changes
{
  id: 5,
  state: 'unpaid',
  _links: {
    self: {
      method: 'GET',
      href: '/orders/5',
    }
    payment: {
      method: 'PUT',
      href: '/orders/5/payments',
    },
    change: {
      method: 'PUT',
      href: '/orders/5/changes',
    }
    cancel: {
      method: 'PUT',
      href: '/orders/5/cancels',
    }
  }
}

PUT /orders/:id/payments
{
  id: 5,
  state: 'paid',
  _links: {
    self: {
      method: 'GET',
      href: '/orders/5',
    }
    take: {
      method: 'PUT',
      href: '/orders/5/takes',
    }
  }
}

PUT /orders/:id/cancels
{
  id: 5,
  state: 'canceled',
  _links: {
    self: {
      method: 'GET',
      href: '/orders/5',
    }
  }
}

PUT /orders/:id/takes
{
  id: 5,
  state: 'completed',
  _links: {
    self: {
      method: 'GET',
      href: '/orders/5',
    }
  }
}