Returns True if the target folder is older than the source folder.

def changes_found(self):
        """
        Returns True if the target folder is older than the source folder.
        """
        if self.dest is None:
            warnings.warn("dest directory not found!")
        if self.src is None:
            warnings.warn("src directory not found!")
        if self.src is None or self.dest is None:
            return False
        dest_mtime = -1
        src_mtime = os.path.getmtime(self.src)
        if os.path.exists(self.dest):
            dest_mtime = os.path.getmtime(self.dest)

        if src_mtime >= dest_mtime:
            return True # changes found

        for folder, _, files in os.walk(self.src):
            for filename in fnmatch.filter(files, '*.scss'):
                src_path = os.path.join(folder, filename)
                if os.path.getmtime(src_path) >= dest_mtime:
                    return True 
        return False