Depends on D4227

Finally, adding the main script. It connects to the local backup service, tries to add a new backup, and then, adds a new log.
Of course, this is a super-early alfa version. In the future, I'm planning to isolate tests for separate services, so for each service, we're going to have a different folder, etc.

This doesn't yet work with docker, I had problems with connecting to other services from rust code run in another container.
You can still run this locally building the code on the host machine:

cd services/commtest
COMM_TEST_TARGET=backup cargo run