Make CI builds use sanitizers for tests

[azonenberg]

It would be nice to run CI tests under asan to catch more bugs at test time.

But we would need to double build because we don't want to have asan enabled for release builds. This will mean splitting every CI configuration to create and run tests for both debug+asan and release configurations (probably no point in doing release+asan as well for now) and only upload binaries for the release version.

[azonenberg]

@Gherkin see above, no rush as this is currently planned for v0.2 but if you wanna poke at this here's the ticket