Merge pull request #4 from n-educatio-pl/master

Added travis directives to check PHP 5.4 and 5.5 as well.
Merge pull request #5 from n-educatio-pl/master

Added ValidatorTemplateFactory and getter checking if all files validated correctly.
1. Refactored Validator (extract method mostly to reveal the author's intention) 2. Added missing Vagrantfile to enable virtual machine creation.