use load_config to load config in jupyterhub_config.py

rather than re-implementing it

tljh/jupyterhub_config.py

@@ -54,13 +54,8 @@ c.SystemdSpawner.default_shell = '/bin/bash'
 # Drop the '-singleuser' suffix present in the default template
 c.SystemdSpawner.unit_name_template = 'jupyter-{USERNAME}'
 
-config_overrides_path = os.path.join(CONFIG_DIR, 'config.yaml')
-if os.path.exists(config_overrides_path):
-    with open(config_overrides_path) as f:
-        config_overrides = yaml.load(f)
-else:
-    config_overrides = {}
-configurer.apply_config(config_overrides, c)
+tljh_config = configurer.load_config()
+configurer.apply_config(tljh_config, c)
 
 # Load arbitrary .py config files if they exist.
 # This is our escape hatch