Windows tests

[fietserwin]

The tests now run successfully on Windows, I hope they still do so as well on Linux...

[fietserwin]

A few notes:

• You require php5.4, but your tests use constructs of 5.5 (:::class) and 7.1 (return :void), so testing on 5.4 will be difficult.
• The test testExtractWithArchiveStreamIsClosed() is expected to throw an ArchiveIOExceptin, but if the check on the open status of the archive fails it will stil throw so on the erroneous out path (i.e. on Linux :)), so you might be getting a false success.

[splitbrain]

Awesome! Thanks for your help.

Testing on older PHP versions is unfortunately not possible because old phpunit versions needed for old PHP versions are not compatible with newer ones. So it's not possible to write tests that run on old and new php unit releases...