Jupyter: Set log-level alias to 'DEBUG' for ipython notebook service

This helps in logging up the requests made by ipython_notebook service

[ kirr: To be clear - until log-level is set to DEBUG, IPython notebook does
  not log HTTP requests, and since logging of HTTP requests is considered normal
  for most of our services (Zope, Apache, etc), it makes sense to enable such
  functionality for notebook too.

  There is not much additional noise produced by --log-level=DEBUG - in
  practice ipython only prints what config files it uses on startup, so this
  should be ok to go. ]

/reviewed-by @kirr, @jerome  (on nexedi/slapos!33)

software/ipython_notebook/instance.cfg.in

@@ -82,6 +82,9 @@ command-line =
   --notebook-dir=${instance-parameter:notebook_dir}
   --logfile=${instance-parameter:logfile}
   --config=${ipython-notebook-config:rendered}
+# Add 'log-level' alias to 'DEBUG' so as to log requests being done while running
+# of service ipython_notebook.
+  --log-level="DEBUG"
 wrapper-path = ${directory:service}/ipython_notebook
 parameters-extra = true
 # Explicitly define IPython Directory to be used while starting ipython notebook

software/ipython_notebook/software.cfg

@@ -60,7 +60,7 @@ recipe = slapos.recipe.template:jinja2
 template = ${:_profile_base_location_}/instance.cfg.in
 rendered = ${buildout:directory}/template.cfg
 mode = 0644
-md5sum = 6bc65c138215dc995e4721cc74bdf7ef
+md5sum = 4608f043f7a1f92064bf1eeab64b55f4
 context =
   key bin_directory buildout:bin-directory
   key develop_eggs_directory buildout:develop-eggs-directory