FunctionalTestCaseBootstrapUtility throws Warnings
unlink can't delete symlinks on Windows systems.
[BUGFIX] FunctionalTestCaseBootstrapUtility throws warnings on Windows
If the FunctionalTestCaseBootstrapUtility::removeInstance() tries to
delete an existing symlink to a folder, the function unlink() is used.
This leads to a warning on Windows systems because unlink can only
delete files and symlinks to files.
This patch adds a rmdir() call for symlinks which works for Windows
system as well.