Fixes bug: The message "[InvalidArgumentException] Test file can't be matched" displayed when exactly one test is running under Windows with the full path to the test.

I am sorry.
Ghost cut out some symbols.

The sample must be as follow:

    <?php
       echo '\\'."\n\n";
       $filename = "tests\\unit\WelcomeTest.php";
       echo $filename."\n";
       echo str_replace('\/', '/', $filename)."\n\n";
       $filename = "tests\/unit\/WelcomeTest.php";
       echo $filename."\n";
       echo str_replace('\/', '/', $filename)."\n";

Results:

    \

    tests\unit\WelcomeTest.php
    tests\unit\WelcomeTest.php

    tests\/unit\/WelcomeTest.php
    tests/unit/WelcomeTest.php