@SRGDamia1, general HMAC functions could benefit all dataPublishers, so I am adding it to the dataPublisherBase. Does that make sense?
Once I get general HMAC SHA256 tokens to work, I'll then be creating a new publisher for Azure EventHubs. AWS IoT has a similar endpoint, so this could be widely used.

but still getting 504.
Also, using SAS generated in Python for now.

Set Port to 443 for HTTPS, and now connecting!
Still getting 504. After using postman, I had thought that the issue was related to Content-Length being wrong, but then I would have gotten a 411 response code.
Tried Transfer-Encoding: chunked, but still 504
Tried adding [] around json, but still 504.

I still can not get this to POST to Event Hub, even with a properly formatted POST Request (that works in Postman). It connects to the server, but gets no response even after 60 seconds.
@SRGDamia1, can you help me figure out #441?

@GArrigotti-cws, @GArrigotti, I also added `platformio.ini` files that you can use for testing on your side.

Connected to #411

Commiting work from 4/20/22.

The key was to use `TinyGsmClientSecure` rather than `TinyGsmClient` in src/modems/SIMComSIM7080.h

Merge `RainVUE` into `develop`

Update `hmac_auth` from `develop`