Make send headers for tx.send

[artpoddybnyy]

Actual

Method tx.send(explorerBasePath, type, data, secretKey, attempts, timeout) don't have opportunity send request headers

Expected

Method tx.send(explorerBasePath, type, data, secretKey, attempts, timeout, headers) have opportunity send request headers

 return _axios2.default.post('' + explorerBasePath, {
    tx_body: txBody
  }, headers}).then...