Verify that a directory exists at the given relative path.
Look for a relative path, ascending through parent directories.
pathToFind: The relative path to look for. startPath: The path to start the search from. If |startPath| is a directory, it will be included in the directories that are searched. endPath: The path to stop searching. testFunc: The function to use to verify the relative path.
Verify that the given relative path exists.