update nb for wpsoutputs path change to bird name (#273)

See PR bird-house/birdhouse-deploy#203

`Makefile` updated for future refresh as well.

Jenkins failure due to wpsoutputs path change:
```
  _________ finch-master/docs/source/notebooks/finch-usage.ipynb::Cell 3 _________
  Notebook cell execution failed
  Cell 3: Cell outputs differ

  Input:
  print("Process status: ", resp.status)
  urls = resp.get()
  print("Link to process output: ", urls.output)

  Traceback:
   mismatch 'stdout'

   assert reference_output == test_output failed:

    'Process stat...20650101.nc\n' == 'Process stat...20650101.nc\n'
    Skipping 77 identical leading characters in diff, use -v to show
    - psoutputs/finch/STATUS_FILE/frost_days_sres_a2_experiment_20460101_20650101.nc
    ?          ------
    + psoutputs/STATUS_FILE/frost_days_sres_a2_experiment_20460101_20650101.nc
```

Makefile

@@ -7,7 +7,7 @@ WPS_URL = http://localhost:5000
 # Used in target refresh-notebooks to make it looks like the notebooks have
 # been refreshed from the production server below instead of from the local dev
 # instance so the notebooks can also be used as tutorial notebooks.
-OUTPUT_URL = https://pavics.ouranos.ca/wpsoutputs
+OUTPUT_URL = https://pavics.ouranos.ca/wpsoutputs/finch
 
 SANITIZE_FILE := https://github.com/Ouranosinc/PAVICS-e2e-workflow-tests/raw/master/notebooks/output-sanitize.cfg