Previously when checking out the repository and installing the source
package via `$ composer install` composer did spill deprecation notices for
four files not complying with the PSR-4 auto-loading standard.
This is a minor issue, composer install works and can be addressed by
fixing name-spaces (all of those three are in tests).
For the one function test, fixing the directory structure / dirname of the
(single) affected function test (fourth file).
