added json file for composer dependency manager
removed includes.php file, convert bootstrapping to composer dependency manager
added and corrected type hints in doc blocks
simplified tests and added type hints
removed require_once statements; added test for computing discounted cash flow
removed require_once statement
introduced phpQuantFinance as the root package for source files of phpQuantFinance project; moved all existing packages into the root package
adapted path to test configuration files
mock classes now constructed using autoload; added phpunit dependency to composer.json
encapsulated function factorial into a class 'Functions'
adapted build path in phpunit config file