Fix `grunt server` for coffeescript angular apps.

Hi,

I hope I understood issue #81 correctly. Otherwise this is a fix for a different issue _grunt server not working for angular apps bootstrapped with --coffee_

Here's the workflow I followed to replicate the issue:

``` bash
$ npm install generator-angular generator-testacular
$ yo angular gruntServerBreaksWithCoffee --coffee
$ npm install && bower install --dev
$ grunt server
```

## Result
app.js and controllers/main.js not loaded
## Cause
Gruntfile.js coffee tast is 
## Fix
1. Set files to [glob](http://gruntjs.com/configuring-tasks) 
2. add a **/*.coffee wildcard search pattern

grunt server now shows the first page