Update boto3 requirement from ~=1.15.18 to ~=1.16.25 (#644)

dependabot[bot] · web-flow · commit 610d6ecd8f5d · 2020-11-26T09:16:45.000+01:00
diff --git a/requirements/requirements.txt b/requirements/requirements.txt
@@ -1,4 +1,4 @@
-boto3~=1.15.18
+boto3~=1.16.25
 cryptography==3.2.1
 marshmallow==3.9.1
 packaging==20.4
