flake8 fixes: unused imports and f-strings without vars

tljh/config.py

@@ -13,7 +13,6 @@ tljh-config show firstlevel.second_level
 """
 
 import argparse
-import asyncio
 from collections.abc import Sequence, Mapping
 from copy import deepcopy
 import os

tljh/installer.py

@@ -16,7 +16,6 @@ import bcrypt
 import pluggy
 import requests
 from requests.packages.urllib3.exceptions import InsecureRequestWarning
-from getpass import getpass
 
 from tljh import (
     apt,
@@ -26,7 +25,6 @@ from tljh import (
     systemd,
     traefik,
     user,
-    utils
 )
 from .config import (
     CONFIG_DIR,

tljh/jupyterhub_config.py

@@ -5,7 +5,6 @@ JupyterHub config for the littlest jupyterhub.
 from glob import glob
 import os
 
-from systemdspawner import SystemdSpawner
 from tljh import configurer
 from tljh.config import INSTALL_PREFIX, USER_ENV_PREFIX, CONFIG_DIR
 from tljh.utils import get_plugin_manager