Tweaks 1

This PR makes three changes:

1. Configures logging to output `>= WARN` to `stderr` and `>= INFO` to `./adam.log`
2. Increases the peak throughput of `bam2adam` by reducing lock contention. When writing to a `nullfs` mount this reduced runtime from 25m to 11m with 16 threads and queue size of 32768.
3. A small change to `scripts/jenkins-test` to run under Ubuntu