In some cases class is not existent, for example if you use class_exists construction. For this case we can prevent crashing.
Added explanation
Merge pull request #26 from damnedest/fix-not-existent-classes

In some cases class is not existent, for example if you use class_exists...
Style tweak
PSR-4 autoloading
Updated the readme
Tweaked the class loader
Updated the license year
Added a test suite
Added travis config