Provides a better error message

Having error.message sometimes provides insufficient feedback: `gulp-notify: [Compile Error] Unexpected token`

Without the .message you get a more details error:
```
./app/assets/coffee/app.coffee:1
alert 'hello world'
      ^
ParseError: Unexpected token
```

I know it's a bad example but you get the point I hope. Let me know if you disagree.