Add stage path to request path if api gateway host

[dabio]

url: https://1234567890.execute-api.us-east-1.amazonaws.com/prod/pets
expected path: /prod/pets
actual path: /pets

This will add the stage path part to the request url path if the host is an aws api gateway host.

[tj]

Hmm I think /pets is a bit more desirable since the app doesn't have to be stage-aware, and the stage can be grabbed from an env var or X-Stage

[dabio]

Okay.