fix dependency version issue

requirements.txt

@@ -4,5 +4,5 @@ netaddr>=0.7.19
 python-ldap>=3.0.0
 PyYAML~=5.1.2
 aiobotocore~=1.0.7
-botocore~=1.5.32
+botocore~=1.15.32
 aiofile~=1.5.2