Fix order of .env loading

[trevor-scheer]

This PR resolves an issue for configless approaches.

A simple reproduction can be achieved by:

// .env
ENGINE_API_KEY=...

$ npx apollo service:push --endpoint=<...>

  ✔ Loading Apollo Project
  ✖ Uploading service to Engine
    → No service found to link to Engine

Cause
This is because the name was being required before loading the env variables, causing an error to be thrown.

Solution
Load the env config earlier in the configuration process so the service name can be inferred if it isn't provided.