Split out the redis hostname for user events and build logs as a string config. Modularize the user events and fix all callers.

app.py

@@ -20,6 +20,7 @@ from util.expiration import Expiration
 from data.billing import Billing
 from data.buildlogs import BuildLogs
 from data.queue import WorkQueue
+from data.userevent import UserEventsBuilderModule
 from license import load_license
 from datetime import datetime
 
@@ -66,6 +67,7 @@ build_logs = BuildLogs(app)
 queue_metrics = QueueMetrics(app)
 authentication = UserAuthentication(app)
 expiration = Expiration(app)
+userevents = UserEventsBuilderModule(app)
 
 tf = app.config['DB_TRANSACTION_FACTORY']
 image_diff_queue = WorkQueue(app.config['DIFFS_QUEUE_NAME'], tf)