Refactor of CLIReporter so that it writes with FileSystem.
Fix checking of , fixes tests
Fixes the filename var
Refactor Reporters. Closes #13
Remove use FileSystem from ReporterInterface
Make CheckstyleReporter actually write the XML as it should
Fixed namespaces in tests
Applied inversion of control to reporters

Because reporters created their own FileSystem, they were unable to be
tested through FileSystem mock.
Removed trailing whitespace
Added CLI reporter test
Merge pull request #19 from HippoPHP/refactor-reporters

Refactor of CLIReporter so that it writes with FileSystem.