Remove manual cleanup() from react-testing-library test suites

[andrelmlins]

Regarding #1615

[louh]

Thank you, @andrelmlins!

We still need to remove the import of cleanup in each test suite, since they're not necessary anymore. You can run npm test from your command line which should let you know which modules still import it but can be removed. Our CI test infrastructure is alerting us to this, as well: https://travis-ci.org/streetmix/streetmix/builds/599424413?utm_source=github_status&utm_medium=notification

Once this is done and tests are passing, we should be good to merge! Thanks again!

[andrelmlins]

Ok @louh

Removed imports from cleanup

[louh]

Excellent. This is good to go. Thank you so much for your contribution! 🚀