correct python version for RTD

[askpatrickw]

fixes #39

[dhalbert]

Let's figure out if we can avoid doing this in some way, because we changed a lot of libraries, and it would be better not to have to update this each time we want to bump versions.

[FoamyGuy]

The RTD error page indicates some other possible versions:

including 3. Perhaps that would behave as wanted 3.x to?

[dhalbert]

readthedocs/readthedocs.org#7814 says it is now possible with readthedocs/readthedocs.org#8453. "Docs to be updated".

[dhalbert]

https://docs.readthedocs.io/en/stable/config-file/v2.html#python-version says python.version is deprecated, and to use build.tools.python (https://docs.readthedocs.io/en/stable/config-file/v2.html#build-tools-python), where you can specify "3" as the version.

Not "3.x", boo hoo. But we'd change to

build:
  tools:
    python: "3"

anyway: https://docs.readthedocs.io/en/stable/config-file/v2.html#build

Could you try that? Thanks.

[dhalbert]

see posts

[askpatrickw]

OK, this builds, I setup a test RTD.

https://test-azureiot.readthedocs.io/en/rtd-python-ver/api.html

It is worth mentioning, that the OS setting is also required and the only allowed value is that one specific Ubuntu version. At some point, that's going to require touching all the repos I bet. :-/

[FoamyGuy]

LGTM, matches recent change merged in cookiecutter repo.