message: return in recursive function
  is this good?
diff: @@ -24,7 +24,7 @@ export function waitUntilTransactionMined(web3: Web3, txnHash: string): Promise<
  let receipt = await web3.eth.getTransactionReceipt(txnHash);
  if (!receipt) {
  setTimeout(function () {
  - transactionReceiptAsync(txnHash, resolve, reject);
  + return transactionReceiptAsync(txnHash, resolve, reject);
  }, POLL_INTERVAL);
  } else {
  resolve(receipt);
  