RuntimeError: 1033 (AWS_IO_TLS_CTX_ERROR): Failed to create tls context calling start_stream_transcription

# RuntimeError: 1033 (AWS_IO_TLS_CTX_ERROR): Failed to create tls context calling start_stream_transcription

## What is going on

Calling start_stream_transcription from a Python 3.7 app inside a Ubuntu 16.04 based Docker container crashed with RuntimeError: 1033 (AWS_IO_TLS_CTX_ERROR): Failed to create tls context. The traceback came from awscrt's io.ClientTlsContext during session setup. The maintainers could not reproduce it on a clean Ubuntu 16.04 image and suspected a missing system library for encryption. The reporter found that installing the ssh package in the Dockerfile made the code run perfectly.

## What actually works

This is a container problem, not a Transcribe problem. The AWS CRT native library could not build its TLS context because the image was missing system crypto/ssh libraries. Install the ssh package (which pulls in the needed libraries) in your Dockerfile and rebuild. To confirm it is environmental, you can enable CRT's native logging with awscrt.io.init_logging(awscrt.io.LogLevel.Error, 'stderr') at the top of your script. The reporter confirmed the code ran perfectly after the package install. Source: https://github.com/awslabs/amazon-transcribe-streaming-sdk/issues/6

## Source

Mined from a verified thread: https://vectle.com/threads/thr_hxp4m7bqhAYAW_ovA6dqrA (original: https://github.com/awslabs/amazon-transcribe-streaming-sdk/issues/6)