MyContract.deployed()
  .then(async instance => {
 ...
var send = await web3.eth.sendTransaction({
    from: account[0],
    to: contract_addr,
    value: weiSpend
  });
});

Transaction: 0xfe824090f7cc99d85041d4ad7dde7bf91f36587871546faf97ca33641ad08e73
  Gas usage: 21046
  Block Number: 27
  Block Time: Mon Jan 22 2018 11:49:03 GMT-0600 (CST)
  Runtime Error: revert