So the below is the function I'm running. I'm sending in the key for this bitcoin address

16WBguy6KVyTGnF4KX7Vmdx8ztj4wENh4W

and the message

bkawk

to this function

// Require the packages that we need.

var bitcoin = require('bitcoinjs-lib');
var request = require('request');
var blockchain = require('blockchain.info');
var blockexplorer = require('blockchain.info/blockexplorer');


// Export the module and pass in the message and the WIF
exports.opReturn = function (message, WIF) {

// Setup the new promise
return new Promise(function(resolve, reject) {    

// Set the network to the main net not test
    var network = bitcoin.networks.mainnet;

 // Generate the keypair
    var keyPair = bitcoin.ECPair.fromWIF(WIF);

// Get the address from the key pair
    var address = keyPair.getAddress();

// Ask blockchain.info for all the unspent transactions 
    var url = 'https://blockchain.info/id/unspent?active='+address;
    request(url, function (error, response, body) {

// Check the request didn't error and we got a 200 ok back
        if (!error && response.statusCode == 200) {

// Parse the results
            var body = JSON.parse(body);


// Build a new transaction
            var tx = new bitcoin.TransactionBuilder(network);

cont...

// Buffer the message into hex
            var data = new Buffer(message);

// Prepare the message
            var dataScript = bitcoin.script.nullDataOutput(data);

// I Suspect there is problems here!!
            var unspent = body.unspent_outputs[0].tx_hash_big_endian;

// Add the unspent tx to the output                
            tx.addInput(unspent, 0);

// Add the unspent transaction to the first output              
            tx.addOutput(dataScript, 0);

// Add our address to the 1st output - Must I use another address or no?
            tx.addOutput(address, 1000);

// Add our address to the 2nd output - Must I use another address here too?
            tx.addOutput(address, 1000);

// Sign the transaction
            tx.sign(0, keyPair);

// Convert to hex
            var txRaw = tx.build().toHex();

            var txId = txRaw.getId()
            console.log(txId);

// Resolve the promise
            resolve(txRaw);

// Log the hex
            console.log(txRaw.toHex());
        } else{

// if there was an error reject the promise
            reject(error);
        };
    })

}); //-- END PROMISE
};// END FUNCTION

the above console.log is giving me this transaction hex

0100000001b4c1870d4e0c6928f40224f465ab7d2c3692fe29e4bc2cc5213776ff128de13f000000006b483045022100a954cdb05753fed2f8afc41619d66dde45e330b1aa75cd5a1d1a03b67392642702203bda25690dac67bed0117fd28ad30fc2cbc16aa778a3b37832aabba9939e344001210298e836ce7df5696bdce02742bb5d7a070b2e5b1ab3535001b71f3615c21c1b1dffffffff030000000000000000076a05626b61776bb80b0000000000001976a9143c5d9d2466274014c2db74dd4738116a193d142788acb80b0000000000001976a9143c5d9d2466274014c2db74dd4738116a193d142788ac00000000

which decoded looks like this

        {
        "lock_time":0,
        "size":242,
        "inputs":[
            {
                "prev_out":{
                    "index":0,
                    "hash":"3fe18d12ff763721c52cbce429fe92362c7dab65f42402f428690c4e0d87c1b4"
                },
                "script":"483045022100a954cdb05753fed2f8afc41619d66dde45e330b1aa75cd5a1d1a03b67392642702203bda25690dac67bed0117fd28ad30fc2cbc16aa778a3b37832aabba9939e344001210298e836ce7df5696bdce02742bb5d7a070b2e5b1ab3535001b71f3615c21c1b1d"
            }
        ],
        "version":1,
        "vin_sz":1,
        "hash":"926eeecb1fc28a34cb8ed14e1e6175ec9012af390b232e26d3c610c345abba47",
        "vout_sz":3,
        "out":[
            {
                "script_string":"OP_RETURN 626b61776b",
                "value":0,
                "script":"6a05626b61776b"
            },
            {
                "script_string":"OP_DUP OP_HASH160 3c5d9d2466274014c2db74dd4738116a193d1427 OP_EQUALVERIFY OP_CHECKSIG",
                "address":"16WBguy6KVyTGnF4KX7Vmdx8ztj4wENh4W",
                "value":3000,
                "script":"76a9143c5d9d2466274014c2db74dd4738116a193d142788ac"
            },
            {
                "script_string":"OP_DUP OP_HASH160 3c5d9d2466274014c2db74dd4738116a193d1427 OP_EQUALVERIFY OP_CHECKSIG",
                "address":"16WBguy6KVyTGnF4KX7Vmdx8ztj4wENh4W",
                "value":3000,
                "script":"76a9143c5d9d2466274014c2db74dd4738116a193d142788ac"
            }
        ]
        }

Pushing it to https://blockchain.info/pushtx returns...

None Standard Script Output OP_RETURN 626b61776b

And pushing here http://blockr.io/tx/push results in

There was an error pushing your transaction to network!

Did you sign your transaction? Is this double spend? Have you already sent this transaction?

but then when I check it here I don't see the transaction. Any Ideas?

https://blockchain.info/address/16WBguy6KVyTGnF4KX7Vmdx8ztj4wENh4W

Here is an example of a successful transaction made from Colu

https://blockchain.info/tx/d831fa05d6bbb2e939e42764945936ee7c23b96a46c173c9e8647d9fe4f0d485?show_adv=true