Create GH/torproject/sbws repository

As commented in network-team ml, we should create:

• a repository called sbws in GH/torproject
• give permissions to pastly, teor, juga to that repository
• push current GH/pastly/simple-bw-scanner master to it
• remove GH/torproject/simple-bw-scanner

When that is done, we can create other ticket to sync that repository with .git.tpo/sbws