I have crated an SPFx app for assets provisioning using this link: https://dev.office.com/sharepoint/docs/spfx/web-parts/get-started/provision-sp-assets-from-package
i have created a list, a content type and a few site columns in it. as an upgrade to the app i create another list. all of these things works fine.
Now i want to create a new content type, add a few more site columns , attach the site columns to the Content type (existing and new).
I tried the upgrade method in the link above , it works for the list creation but does not work for site column or content type creation.