get rivision from env

app/routes/api_v1/endpoints/semesters.py

+import os
 from typing import List
 
 from fastapi import APIRouter, Depends
@@ -19,4 +20,4 @@ def see_all_available_semesters(broker: Broker = Depends(get_database_broker)):
 
 @router.get("/revision", response_model=int)
 def see_current_data_revision():
-    return 1
+    return os.environ.get("REVISION", 1)