List all the bootstraps available to build with.

def bootstraps(self, _args):
        """List all the bootstraps available to build with."""
        for bs in Bootstrap.list_bootstraps():
            bs = Bootstrap.get_bootstrap(bs, self.ctx)
            print('{Fore.BLUE}{Style.BRIGHT}{bs.name}{Style.RESET_ALL}'
                  .format(bs=bs, Fore=Out_Fore, Style=Out_Style))
            print('    {Fore.GREEN}depends: {bs.recipe_depends}{Fore.RESET}'
                  .format(bs=bs, Fore=Out_Fore))