Catch up to ooni

This catches up to the Ooni master branch as of today, which fixes #41. Note that this includes the changes in pull request #59. I advise merging manually, since we have lots of branches.
I believe you should add an extra key here: 

```
dns_discovery:
    address: Null
    udp_port: Null
    tcp_port: Null
    resolver_address: Null
```