move slackwebhook migration from tools to util

tools isn't shipped inside of the container because it contains private
keys

util/migrateslackwebhook.py

@@ -0,0 +1,52 @@
+import logging
+import json
+
+from app import app
+from data.database import configure, RepositoryNotification, ExternalNotificationMethod
+
+configure(app.config)
+
+logger = logging.getLogger(__name__)
+
+def run_slackwebhook_migration():
+  slack_method = ExternalNotificationMethod.get(ExternalNotificationMethod.name == "slack")
+
+  encountered = set()
+  while True:
+    found = list(RepositoryNotification.select().where(
+                      RepositoryNotification.method == slack_method,
+                      RepositoryNotification.config_json ** "%subdomain%",
+                      ~(RepositoryNotification.config_json ** "%url%")))
+
+    found = [f for f in found if not f.uuid in encountered]
+
+    if not found:
+      logger.debug('No additional records found')
+      return
+
+    logger.debug('Found %s records to be changed', len(found))
+    for notification in found:
+      encountered.add(notification.uuid)
+
+      try:
+        config = json.loads(notification.config_json)
+      except:
+        logging.error("Cannot parse config for noticification %s", notification.uuid)
+        continue
+
+      logger.debug("Checking notification %s", notification.uuid)
+      if 'subdomain' in config and 'token' in config:
+        subdomain = config['subdomain']
+        token = config['token']
+        new_url = 'https://%s.slack.com/services/hooks/incoming-webhook?token=%s' % (subdomain, token)
+        config['url'] = new_url
+
+        logger.debug("Updating notification %s to URL: %s", notification.uuid, new_url)
+        notification.config_json = json.dumps(config)
+        notification.save()
+
+if __name__ == "__main__":
+  logging.basicConfig(level=logging.DEBUG)
+  logging.getLogger('boto').setLevel(logging.CRITICAL)
+
+  run_slackwebhook_migration()