Make Changes for adding and firing events

[rajivseelam]

There are two problems which I faced:

$ready = new \Khill\Lavacharts\Events\Ready('readyCallBack');

$linechart->events([$ready]);

This was throwing an error because of namespacing problem. is_subclass_of($event, '\Lavacharts\Events\Event') returns false.

2nd Problem:

Registering for events like 'ready' show be done before calling draw. So I have just shifted the position to before draw during render.

[coveralls]

Coverage remained the same when pulling 6eb2cf8 on rajivseelam:events_not_fired into 2ceb97b on kevinkhill:master.

[kevinkhill]

I'm on mobile so I can't do much, but your fixes look good. When I get time, I'll test your fixes and merge them in. Thank you for swatting some bugs!