Stop drupal.org tarball support and direct towards a full composer workflow.

Problem/Motivation

Right now we still have tarballs being created by Drupal, which is neat. But it doesn't really work. For all the third party libraries we use we still need to use composer and this is confusing for our end-users trying to install Open Social. They are better of using composer from the start, it means easier updates, less prone to bugs (modules forgotten to be download / installed, version compatibility) etc.

Also creating these tarballs is done using drush make, however right now nobody is maintaining drush make and with the new semver versioning the tarballs are not being picked up anymore correctly. As in, the semver support is not there for drush make while we do want to make a move in to that versioning direction. Otherwise we will not be able to start rolling out 9.x.x releases in the near future just because the make files don't accept this.

Proposed resolution

After a chat in the drupal infrastructure slack (June 10th) we noticed:

Actually, I hope distributions converge on a standard way to install via Composer, regardless of packaging, so we can put those on release pages and in the Downloads section of the project page. (like core packaging uses composer create-project now)

That would be nice. We are using composer as a standard from the beginning, but we have a tarball just to create proper releases on d.o

drush make isn’t a requirement for the releases being published. Just if there are .make files, they have to validate/etc.

With that in mind, and our composer template being available at:
We have this available here: https://github.com/goalgorilla/social_template/
Using the: composer create-project goalgorilla/social_template:dev-master DIRECTORY --no-interaction command

We will move in to the composer direction and see if we can get the ball rolling on perhaps getting the Drupal packaging script to allow for composer create-project commands to be used.