message: Minor updates of payment design.
diff: @@ -464,12 +464,14 @@ pub fn indy_parse_get_utxo_response(command_handle: i32,
  ///
  /// #Returns
  /// payment_req_json - Indy request for doing tokens payment
  +/// payment_method
  pub fn indy_build_payment_req(command_handle: i32,
  inputs_json: *const c_char,
  outputs_json: *const c_char,
  cb: Option<extern fn(command_handle_: i32,
  err: ErrorCode,
  - payment_req_json: *const c_char) -> ErrorCode>) -> ErrorCode {}
  + payment_req_json: *const c_char,
  + payment_method: *const c_char) -> ErrorCode>) -> ErrorCode {}
  /// Parses response for Indy request for payment txn.
  ///
  @@ -506,11 +508,13 @@ pub fn indy_parse_payment_response(command_handle: i32,
  ///
  /// #Returns
  /// mint_req_json - Indy request for doing tokens minting
  +/// payment_method
  pub fn indy_build_mint_req(command_handle: i32,
  outputs_json: *const c_char,
  cb: Option<extern fn(command_handle_: i32,
  err: ErrorCode,
  - mint_req_json: *const c_char) -> ErrorCode>) -> ErrorCode {}
  + mint_req_json: *const c_char,
  + payment_method: *const c_char) -> ErrorCode>) -> ErrorCode {}
  /// Builds Indy request for setting fees for transactions in the ledger
  ///
  