Select the Salesforce Release for a Scratch Org

[idanblich]

Stating next release (September 6, 2019) we should be able to create Preview Scratch Org
Salesforce DX Developer Guide.
However the option is not available by autocomplete in the org definition file.
Please add the option : "release": "Preview"

[lcampos]

Thanks for opening this request, we'll make sure to include this.
cc @ntotten