test(inmem): re-enable skipped CreateBucket test
test(inmem): re-enable skipped CreateBucket test

I don't know why it was skipped originally, but I ran it under the race
detector for tens of thousands of iterations and couldn't get it to
fail.

influxdb/influxdb,mark-rushakoff/influxdb,nooproblem/influxdb,nooproblem/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,influxdata/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,influxdb/influxdb,nooproblem/influxdb,influxdb/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,li-ang/influxdb,nooproblem/influxdb,nooproblem/influxdb,li-ang/influxdb,influxdata/influxdb,influxdb/influxdb