README example does not run due to missing VERSION_KEY

[james-pcdr]

Hello all,
I'm just starting to learn about SigMF. I tried the "Create and save..." example from the homepage, and it gave an error saying 'core:version' is a required property.

Possible solutions:

1. Add the version to the example:

global_info = {
    SigMFFile.VERSION_KEY: "1.0.0",
    ...

2. Make 1.0.0 default? In this comment, it looks like perhaps that was intended 🤷‍♂️.

Thanks all for making SigMF!

[Teque5]

Yep I think we broke this just recently, need to create a bugfix.

It should use the sigmf.__specification__ value, which is currently 1.2.0.

Thanks for opening the issue.