503 Service Temporarily Unavailable

# ISSUE
At the final step, once I copied the `BooksApiEndpoint`, and browsed that endpoint, I got the mentioned error `503 Service Temporarily Unavailable`.

# ERRORS
Within `CloudWatch` I can see the following error
```
exec /usr/local/bin/ruby: exec format error
```

# NOTES
- All of the `stacks` were successful with 0 errors.
- The local test of the app (Dockerfile) was successful.