function toAddress(publicKey) {
  // normalize key
  publicKey = decompress(publicKey);
  var addressBuffer = pubToAddress(toBuffer(addLeading0x(publicKey)));
  var checkSumAdress = toChecksumAddress(addLeading0x(addressBuffer.toString('hex')));
  return checkSumAdress;
}
generates the ethereum-address of the publicKey
We create the checksum-address which is case-sensitive
@returns {string} address