Does not build on ARM64. Requires dependency update.

[thingstiger]

This project does not currently build on ARM64 due to awslabs/aws-crt-python#228
This has already been fixed in awscrt which is a dependency of awsiotsdk.
Updating to the latest version of awsiotsdk in requirements.txt will resolve this build problem on arm64.
Updating awscrt seems to cause a small change in behaviour. Only the root CA cert must be provided in DER instead of PEM format or else the TLS context can't be set up.
If you run into any other problems then io.init_logging(awscrt.io.LogLevel.Trace, 'stdout') is your friend.

[fernau]

Edit: I've updated the IoT SDK and awscrt and the expected root CA file format is now back to PEM format.