Added friends function
Implementing 'activity/friends' call
Added Friends.php
Updated gitignore
Changed passing parameters when calling an api call class.

Also, the run() method needs to be called on each request to get the result. When using Trakt::post(), the second parameter is removed and you need to un setParameters() to set the parameters for a post request
Added TraktException
Deletet unused @throws comment
Now throws TraktException instead of \Exception
Now expects TraktException instead of \Exception
Now expects TraktException instead of \Exception
Added new test
Now expects TraktExeption instead of \Exception