Patrick McAndrew

I believe the params section can be used to achieve something close (empty env var vs not set). ``` { provider: { environment: { LOCAL_SNS_ENDPOINT: "${param:local_sns_endpoint}" } }, params: {...

@colesiegel - see https://www.serverless.com/framework/docs/guides/parameters - the param corresponding to the stage is automatically set. Admittedly for this example the `LOCAL_SNS_ENDPOINT` would be empty string instead of not set for any...