code: function getKeys (secret) {
  	var hash = crypto.createHash('sha256').update(secret, 'utf8').digest();
  	var keypair = naclInstance.crypto_sign_keypair_from_seed(hash);
  
  	return {
  		publicKey : Buffer.from(keypair.signPk).toString('hex'),
  		privateKey : Buffer.from(keypair.signSk).toString('hex')
  	};
  }
docs: @method getKeys
  @param secret string
  
  @return {object}