Download User Migration Archive

Fetches the URL to download the migration archive as a `tar.gz` file. Depending on the resources your repository uses, the migration archive can contain JSON files with data for these objects: * attachments * bases * commit\_comments * issue\_comments * issue\_events * issues * milestones * organizations * projects * protected\_branches * pull\_request\_reviews * pull\_requests * releases * repositories * review\_comments * schema * users The archive will a...