message: Updated Libvcx to match new function signature
diff: @@ -103,7 +103,7 @@ pub fn libindy_get_txn_author_agreement() -> VcxResult<String> {
  let mut author_agreement_data = get_author_agreement_response["result"]["data"].as_object()
  .map_or(json!({}), |data| json!(data));
  - let get_acceptance_mechanism_request = ledger::build_get_acceptance_mechanism_request(Some(&did), None)
  + let get_acceptance_mechanism_request = ledger::build_get_acceptance_mechanism_request(Some(&did), None, None)
  .wait()
  .map_err(map_rust_indy_sdk_error)?;
  