fixed linting and tests

cellxgene_gateway/cache_entry.py

@@ -168,9 +168,8 @@ class CacheEntry:
                 headers[h] = request.headers[h]
 
         full_path = self.cellxgene_basepath() + subpath + querystring()
-
+        cellxgene_response = None
         try:
-            cellxgene_response = None
             if request.method in ["GET", "HEAD", "OPTIONS"]:
                 cellxgene_response = get(full_path, headers=headers)
             elif request.method == "PUT":