Test newer Tor versions in our CI

[robgjansen]

We currently only test a limited number of Tor versions in our CI. We should:

• update to the latest point release for of each the stable releases we currently test ('0.3.5.7', '0.4.0.5', '0.4.1.8')
• Add more recent stable releases to the list of those we test

This may introduce bugs that we should fix. For example, we noticed in #101 that there seems to be a SOCKS handshake bug when using TGen v1.0.0 with Tor v0.4.2.6. These bugs should be fixed so we can better support newer Tor versions.

It would also be cool if we could add Github action badges for each Tor versoin to the top-level README so everyone could tell which Tor versions are tested, which are currently passing the CI, and which are failing.