Implemented stats for external CIs

All CI votes are collected in new records with type 'ci_vote'. All standard statistics are
available for these records. Also added a new "CI Status" report that shows summary of CI
tests execution on merged patch sets, overall summary and results per merged change requests.

List of CIs is taken from DriverLog's repo.

Change-Id: Ic7a830dc5b331ba4c099be458ad2bab4c2072607

stackalytics/dashboard/helpers.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import datetime
+import operator
 import re
 
 import six
@@ -116,7 +117,8 @@ def get_activity(records, start_record, page_size, query_message=None):
         records = [r for r in records
                    if (r.get('message') and
                        r.get('message').find(query_message) > 0)]
-    records_sorted = sorted(records, key=lambda x: x['date'], reverse=True)
+    records_sorted = sorted(records, key=operator.itemgetter('date'),
+                            reverse=True)
 
     result = []
     for record in records_sorted[start_record:]: