Use PSR-4 Autoloader

v3.0.0

Fix: PSR-4 Autoload

v2.1.0: Merge pull request #3 from ickbinhier/patch-2

add checkdomain/holiday version 3

v2.0.1

Merge pull request #1 from ickbinhier/patch-1

quoting the scalar

v2.0.0

Fix: Dependency for version 2.0

v1.0.0

Fix: Added version and dependency