Category page

You can look through the category page with its subcategories which contain tests. 
Also there is a hint on each test to see whole name of current test.
don't repeat yourself (DRY)!
refactor this to function like

``` javascript
function getSubcat(id) {
    return $httpBackend.whenGET('http://localhost:9292/categories/subcat/' + id).respond(subcategories[id]);
}
```