Generate the root directory root if it doesn't already exist

def initialize(self):
        """ Generate the root directory root if it doesn't already exist """
        if not os.path.exists(self.root_dir):
            os.makedirs(self.root_dir)
        assert os.path.isdir(self.root_dir), "%s is not a directory! Please move or remove it." % self.root_dir
        for d in ["bin", "lib", "include"]:
            target_path = os.path.join(self.root_dir, d)
            if not os.path.exists(target_path):
                os.makedirs(target_path)
        if not os.path.exists(self.manifest_path):
            open(self.manifest_path, "w+").close()
        self.new = False