Update composer autoload path

When trying to autoload the spomky-labs/otphp library through composer, I was getting an error about not being able to find the class.

I checked in the ```lib/vendor/composer/autoload_namespaces.php``` file and noticed that composer was looking for the library in ```$vendorDir/spomky-labs/otphp/lib``` when it really should be looking in ```$vendorDir/spomky-labs/otphp/Spomky/OTPHP/lib```. 

I forked the repo, changed the composer.json file, and tested it in my project. Once I made the update, it autoloaded correctly.