Update our tests.

[bintzandt]

Summary

@atimmer mentioned in #128 that we should try to change the testing environment from jsdom to node. Since this is an issue that is present in more packages than the analysis-report package alone, I decided that it might be better to create an issue for this.

In the same issue, he also mentioned that we prefer describe and it over test. I suspect that test is also used more broadly than this package alone.

This way, we can evaluate what needs to be done and why. It also allows #128 to move through the process.

I discussed with @diedexx before creating this issue and he agrees with me that it might be better to tackle this issue globally instead of on a per package basis.

Explanation

Open a discussion on how we want to test.

Feedback?

@atimmer probably has some feedback for this.