Suggestion: Change consentToken to apiAccessToken

[Whobeu]

Per the developer documentation at https://developer.amazon.com/docs/custom-skills/device-address-api.html#get-the-api-access-token-and-device-id, consentToken is now deprecated and apiAccessToken should be used instead. Updating the index.js code to reflect this change would help new developers. Suggest changing the code to:

const accessToken = requestEnvelope.context.System.user.permissions
      && requestEnvelope.context.System.apiAccessToken;

if (!accessToken) {