Moving code to PSR-4

                    
|Q             |A  |
|---           |---|
|Bug Fix?:     |n  |
|New Feature?: |y  |
|BC Breaks?:   |n  |
|Deprecations?:|n  |
|Tests Pass?:  |y  |
|Fixed Tickets:|#48   |
|License:      |MIT|
|Doc PR:       |   |
                    

Also changes the KeenIOClient::__call() method, so it doesnt override the normal parameters. Makes it so Mockery cant mock it