Suport for paper and live

[maimas]

Description

Extended current configuration to allow both paper and live trading modes in the same cloud formation deployment

Key changes

1. Branched credentials for live and paper clients.
2. Updated alpaca_service.ts so that it can handle paper and live events
3. Updated app.ts - added one hander for each mode
4. Added one more resource in cloud formation yaml file - exposed live and paper endpoints.

Testing

Didn't have a chance to test it yet

[maimas]

This is a draft PR, @vladislavmunteanu what do you think?

[vladislavmunteanu]

This is a draft PR, @vladislavmunteanu what do you think?

I love it! 💯