Update CircleCI for `master-1.x`, `1.9`, `1.8` to collect test results

The `test` job in our 1.x CI runs unit tests, but doesn't collect results for display in Circle's UI. This makes finding failures more difficult.

Update the CI to generate and collect test-result files. This will require switching over to use `gotestsum`. For reference, [this](https://github.com/influxdata/influxdb/blob/master/.circleci/config.yml#L406-L416) is how the 2.x line does it.

Inspect the CircleCI configuration for the master-1.x, 1.9, and 1.8 lines, focusing on the test job, and compare it with the referenced .circleci/config.yml section from the 2.x line. Check how gotestsum is used there, then verify that the 1.x test jobs generate and collect result files for CircleCI's test-results display.

Written by the indexing model from the issue text.