Fix unit tests in git-temporal-react

[littlebee]

This is mia culpa. During the last big redesign and refactor I made an intentional decision to not update the unit tests for git-temporal-react. I didn't know if this would be The final design/layout and didn't want to update them n more times.

When the tests in gtr last worked, they were running at about 90% coverage. I'm less concerned with overall coverage percentage these days and would prefer better tests instead of more coverage. I've also never been entirely sure that shallow unit tests provide as much peace of mind as good integration or end to end testing. I will add another ticket for doing the E2E test work.

Requirements:

• Let's shoot for >= 70% cov and some quality unit tests that aren't all just snapshot testing?.
• All tests that are there should pass
• Quality tests around the reselect selectors

[littlebee]

One of the issues I've encountered so far is with the use of Enzyme not supporting hook functions with shallow rendering. This is a known thing with Enzyme.

Kinda been rethinking testing in general and am wondering if it would be better to adopt the practices backing React Testing Library

I think this will end up being dependent on upgrading react-redux #22