"Failed to create CloudFormation change set: No updates are to be performed." generates error code -1

Hello,

When calling deploy-serverless with a package created with package-ci command, the second time I call the command with the same package I get this as an error message: "Failed to create CloudFormation change set: No updates are to be performed." and the cli tool returns with exit code -1

This is processed by the most CI tools (for example Teamcity - the one I use) as an error, and the build fails.

I think the normal behavior, at least from the "deploy-serverless" point of view should be not to return exit code -1. I don't know if the aws-sdk-net should return ChangeSetStatus.FAILED or not, probably this is somehow another discussion (that should happen in the aws-sdk-net project, since there is no special status like SKIPPED), but as a user of "deploy-serverless" function I believe this should only seen as a warning, not an error. Even if this means checking the error message I guess.