Create installation script for oonib

To facilitate the deployment of oonib on server we should have a script that automates the deployment of it.

Such script should basically do what is documented here: https://gitweb.torproject.org/ooni-probe.git/blob/HEAD:/oonib/README.md.

For the time being I would omit the part where we automate the installation of a tor2web mode patched tor binary.