Mark Storage.url overrides as keyword-only arguments

This was already implicitly encouraged by the documentation and API structure,
but this change ensures that callers will always pass arguments correctly.
Since all additional arguments to `.url` are non-standard (compared to Django
`Storage`) and vary across Django-Storages subclasses, calling with positional
arguments should be disallowed.

This is technically a breaking change for anyone using positional arguments,
though the fix should be obvious.

Author: brianhelba

storages/backends/azure_storage.py

@@ -293,7 +293,7 @@ def _expire_at(self, expire):
         # azure expects time in UTC
         return datetime.utcnow() + timedelta(seconds=expire)
 
-    def url(self, name, expire=None, parameters=None, mode="r"):
+    def url(self, name, *, expire=None, parameters=None, mode="r"):
         name = self._get_valid_path(name)
         params = parameters or {}
         permission = BlobSasPermissions.from_string(mode)

storages/backends/gcloud.py

@@ -309,7 +309,7 @@ def get_created_time(self, name):
         created = blob.time_created
         return created if setting("USE_TZ") else timezone.make_naive(created)
 
-    def url(self, name, parameters=None):
+    def url(self, name, *, parameters=None):
         """
         Return public URL or a signed URL for the Blob.
 

storages/backends/s3.py

@@ -665,7 +665,7 @@ def get_modified_time(self, name):
         else:
             return make_naive(entry.last_modified)
 
-    def url(self, name, parameters=None, expire=None, http_method=None):
+    def url(self, name, *, parameters=None, expire=None, http_method=None):
         # Preserve the trailing slash after normalizing the path.
         name = self._normalize_name(clean_name(name))
         params = parameters.copy() if parameters else {}