Bump marshmallow from 3.8.0 to 3.9.1 (#630)

dependabot[bot] · web-flow · commit 2bd9ca93a09b · 2020-11-11T16:16:15.000+01:00
diff --git a/requirements/requirements.txt b/requirements/requirements.txt
@@ -1,6 +1,6 @@
 boto3~=1.15.18
 cryptography==3.2.1
-marshmallow==3.8.0
+marshmallow==3.9.1
 packaging==20.4
 PyYAML>=5.1,<5.4
 requests==2.24.0
