Make config check skippable for tests

restic_volume_backup/config.py

@@ -2,10 +2,12 @@ import os
 
 
 class Config:
-    def __init__(self):
+    def __init__(self, check=True):
         self.repository = os.environ['RESTIC_REPOSITORY']
         self.password = os.environ['RESTIC_PASSWORD']
         self.docker_base_url = os.environ.get('DOCKER_BASE_URL') or "unix://tmp/docker.sock"
+    
+        if check:
             self.check()
 
     def check(self):