Logging page errors

Hello! I am having some weird javascript errors on the page when using backstop.js. I've the following in my `onBefore.js` to log errors, but I'm not seeing anything - am I missing something?

```
module.exports = function(casper, scenario, vp) {
//This script runs before your app loads. Edit here to log-in, load cookies or set other states required for your test.

console.log('onBefore.js starting')

casper.wait(1000, function() {

});

casper.on("remote.message", function(msg) {
console.log("Console: " + msg);
});

casper.on("page.error", function(msg, trace) {
console.log("Error: " + msg);
});

casper.on("resource.error", function(msg, trace) {
console.log("Res.Error: " + msg);
});

console.log('onBefore.js has run for ' + vp.name + '.');
};
```