Part of https://github.com/ooni/probe/issues/1335.
Motivation: we want all workflows to be green only when we are
approaching a release. It's fine if some less core tests are
failing during the development process. We have daily builds anyway
so we know of new breakages the day after, which is OK.
* Use ooni/probe-engine 0.16.0
* Update all the other dependencies
* Use GitHub Actions rather than Travis CI
* Automatically build and test binaries on the target OS (for Windows, macOS, Linux on amd64)
* Make sure we correctly measure coverage
* Make sure we use `-race` when running tests
* Remove unnecessary scripts
* Make sure the README is up-to-date
* Write small script to update binary data and add GitHub Actions checks for it
* Notice that we needed to run ./updatebindata.sh and run it
* Self documenting instructions regarding cross compiling
* Set version number to v3.0.7-beta
Part of https://github.com/ooni/probe-engine/issues/748