Baseline comparison "passes" when baseline absent

[cbegeman]

When a baseline is not provided, the output from running the tasks includes baseline comp.: PASS. This line should either be removed or replaces with something like baseline comp.: N/A

For example:

polaris calling: polaris.run.serial._run_task()
  in /global/u1/c/cbegeman/polaris-repo/ocn-enhance-convergence-analysis/polaris/run/serial.py

Running steps: init_200km, forward_200km, init_100km, forward_100km, init_50km, forward_50km, init_25km, forward_25km, analysis
  * step: init_200km
          already completed
  * step: forward_200km
          already completed
  * step: init_100km
          execution:        SUCCESS
          runtime:          0:00:03
  * step: forward_100km
          execution:        SUCCESS
          runtime:          0:00:16
  * step: init_50km
          execution:        SUCCESS
          runtime:          0:00:02
  * step: forward_50km
          execution:        SUCCESS
          runtime:          0:00:12
  * step: init_25km
          execution:        SUCCESS
          runtime:          0:00:07
  * step: forward_25km
          execution:        SUCCESS
          runtime:          0:00:15
  * step: analysis
          execution:        SUCCESS
          runtime:          0:00:01
  task execution:   SUCCESS
  baseline comp.:   PASS
  task runtime:     0:00:56
Task Runtimes:
0:00:56 PASS ocean/planar/inertial_gravity_wave
Total runtime: 0:00:59
PASS: All passed successfully!