message: Add charge succeeded
diff: @@ -6,6 +6,7 @@ use resources::{Charge, Invoice};
  pub enum EventType {
  #[serde(rename = "invoice.created")] InvoiceCreated,
  #[serde(rename = "invoice.updated")] InvoiceUpdated,
  + #[serde(rename = "charge.succeeded")] ChargeSucceeded,
  }
  #[derive(Debug, Deserialize)]
  