Reorganise NewAccount to exit early if account already exists (#93)
Reorganise NewAccount to exit early if account already exists (#93)

Previously if the request body were nil, a ToS not accepted error would be returned. This changes the behaviour to return 200 regardless of the request body if an account already exists.
shred/pebble,letsencrypt/pebble,letsencrypt/pebble,letsencrypt/pebble,shred/pebble