provider vps configuration missing from default cirrus.yml provider settings

[jkeifer]

Somehow I missed that the VPC settings needed to be configured both in the provider block and in the custom batch block. Of course I think batch could reference the provider settings and we don't even need the batch one.

Regardless, this needs to be updated in the default template, and will be a breaking change for end users if we remove the batch settings expectation. Without it, lambda functions are not run within the specified VPC security group/subnets.