Update README: Replace API Key with Auth Token and Reflect Changes in…

[sbrij001]

… YAML File

Contributing to Twilio

All third-party contributors acknowledge that any contributions they provide will be made under the same open-source license that the open-source project is provided under.

• [ x] I acknowledge that all my contributions will be made under the project's license.

[sbrij001]

@bnb Will you review this PR?

[bnb]

Should also be merged with #73

[ayyrickay]

@sbrij001 merging these in to close this out