message: Add update invoice function and doc notes
diff: @@ -135,10 +135,17 @@ impl Invoice {
  client.post_empty(&format!("/invoices/{}/pay", invoice_id))
  }
  - // Lists all invoices with optional customer_id and limit params
  - // TODO: Implement InvoiceListParams
  + /// Updates an invoice.
  + ///
  + /// For more details see https://stripe.com/docs/api#update_invoice.
  + pub fn update(client: &Client, invoice_id: &str, params: InvoiceParams) -> Result<Invoice, Error> {
  + client.post(&format!("/invoices/{}", invoice_id), &params)
  + }
  +
  + /// Lists all invoices with optional customer_id and limit params
  + ///
  + /// For more details see https://stripe.com/docs/api#list_invoices.
  pub fn list(client: &Client, params: InvoiceListParams) -> Result<List<Invoice>, Error> {
  client.get(&format!("/invoices?{}", query::to_string(&params)?))
  - // client.get(&format!("/invoices?customer={}", customer_id))
  }
  }
  