Coverage gets generated on every build, but we only need to send it for
one build. Send it on the first one, otherwise we get eg:
./cc-test-reporter after-build --exit-code $TRAVIS_TEST_RESULT
time="2019-08-22T12:37:01Z" level=warning msg="Conflict when uploading: A test report for commit 6dabaaa6cd7e4c5c51dc538e4fbb7861ca433d8e already exists, skipping upload"
I guess this is because the test reporter assumes that if coverage
exists, then it has been sent?
Config from here:
https://docs.codeclimate.com/docs/travis-ci-test-coverage#section-travis-ci-single-test-suite-non-parallel-builds
