news: add entry for axoflow#318

Signed-off-by: Attila Szakacs <[email protected]>

news/bugfix-318.md

@@ -0,0 +1,6 @@
+`s3()`: Eliminated indefinite memory usage increase for each reload.
+
+The increased memory usage is caused by the `botocore` library, which
+caches the session information. We only need the Session object, if
+`role()` is set. The increased memory usage still happens with that set,
+currently we only fixed the unset case.