When using  ToastService#error there are console warnings. 

Here are the warnings.

```
attempted to use unregistered theme 'warn'
Attempted to use unregistered theme 'warn'. Register it with $mdThemingProvider.theme().
attempted to use unregistered theme 'warn'
Attempted to use unregistered theme 'warn'. Register it with $mdThemingProvider.theme().
```

I know these are just warnings, but because this is a starter I think it should not contain them.
