message: [faucet server] fix error message
  for transactions that exceeds hard limit, amount should be displayed in libras(not microlibras)
diff: @@ -60,7 +60,7 @@ def send_transaction():
  return 'Bad amount', 400
  if amount > MAX_MINT:
  - return 'Exceeded max mint amount of {}'.format(MAX_MINT), 400
  + return 'Exceeded max mint amount of {}'.format(MAX_MINT / (10 ** 6)), 400
  application.client.sendline("a m {} {}".format(address, amount / (10 ** 6)))
  application.client.expect("Mint request submitted", timeout=2)
  