In order to extend the recognition of runfiles, tests need to be added
before any code change. PHPUnit and vfsStream have been chosen as tools
for this task and added as dev-requirement through composer.
The existing runfile name tests are located in test/phake/test folder,
which is written into composers PSR-0-compliant autoloader section.
PHPUnit configuration is straightforward and just bootstraps composers
Merge efforts for tests from upstream laongside with the lowercase
runfile recognition feature and their respective tests. The tests folder
was changed in favor of upstream definition.
PHPUnits bootstrap now uses the autoloader in order to benefit from
autoloading for test classes as well. The composer.json file reflects
PHPUnit and vfsStream dependecies (as dev).