Cleaned up some tests & prepare 3.0

[Nyholm]

Just making sure tests are passing.

I removed Travis because it is super slow.

The tests that fail is just because they need to add some return annotations. This is fine since we are doing a new major release.

[Nyholm]

@dbu I want to merge this and release 3.0.

[dbu]

thanks for the cleanups. do you want to keep the failing builds or should we disable them until somebody finds time to fix them?

[Nyholm]

We should keep them. This CI just want to check how "other clients" behave with the suggested changes.