civi-download-tools - Add "--quiet" and "--force". Don't run "composer" unless the json has changed
civibuild - Automatically download new/updated tools

This is a small workflow improvement. It doesn't improve DX for initial
installation (because 'amp config' and 'amp test' should run before
'civibuild'), but it will improve DX for subsequent updates/upgrades.
Merge pull request #15 from civicrm/master-auto-download

Automatically download new/updated tools