Feature request: Unique API Gateway names pr. stage

Since Chalice prefer to generate different API's instead of different stages when specifying a stage, it would be great if the API's actually had the environment prefixed. Otherwise it makes it really tricky in the console when mapping to a custom domain, or generally looking at things through the console.

https://github.com/aws/chalice/blob/master/chalice/deploy/deployer.py#L803 even has a mention of its usefulness, so i figured it might as well need an actual issue for tracking.