Add some logging to notify_impact.

This will aid in debugging DocImpact when its not working quite right.

Change-Id: Iabcb71808224ed2c62e697ce3715f50982d23434
diff --git a/jeepyb/cmd/notify_impact.py b/jeepyb/cmd/notify_impact.py
index 029c5d2..9c505a3 100644
--- a/jeepyb/cmd/notify_impact.py
+++ b/jeepyb/cmd/notify_impact.py
@@ -31,6 +31,7 @@
 from __future__ import print_function
 
 import argparse
+import logging
 import os
 import re
 import smtplib
@@ -43,6 +44,9 @@
 
 from jeepyb import projects
 
+
+logger = logging.getLogger('notify_impact')
+
 BASE_DIR = '/home/gerrit2/review_site'
 EMAIL_TEMPLATE = """
 Hi, I'd like you to take a look at this patch for potential
@@ -140,6 +144,11 @@
     author_class = None
 
     buginfo, buglink = actions.create(project, bug_title, bug_descr, args)
+    logger.info('Created a bug in project %(project)s with title "%(title)s": '
+                '%(buglink)s'
+                % {'project': project,
+                   'title': bug_title,
+                   'buglink': buglink})
 
     # If the author of the merging patch matches our configured
     # subscriber lists, then subscribe the configured victims.
@@ -154,6 +163,9 @@
         config = config.get('subscriber_map', {}).get(author_class, [])
         for subscriber in config:
             actions.subscribe(buginfo, subscriber)
+            logger.info('Subscribed %(subscriber)s to bug %(buglink)s'
+                        % {'subscriber': subscriber,
+                           'buglink': buglink})
 
     return buglink