Trial running Sentry in Admin

This will capture and send various events to Sentry:

- Any unhandled exceptions.
- Any logger.error calls.
- Some request traces.

The latter are severely limited to avoid going over the free tier
limits for Sentry, and to avoid excess effort on our end.

application.py

@@ -1,7 +1,20 @@
+import os
+
+import sentry_sdk
 from flask import Flask
+from sentry_sdk.integrations.flask import FlaskIntegration
 
 from app import create_app
 
+sentry_sdk.init(
+    dsn=os.environ['SENTRY_DSN'],
+    integrations=[FlaskIntegration()],
+    environment=os.environ['NOTIFY_ENVIRONMENT'],
+    attach_stacktrace=True,
+    traces_sample_rate=0.00005  # avoid exceeding rate limits in Production
+)
+sentry_sdk.set_level('error')  # only record error logs or exceptions
+
 application = Flask('app')
 
 create_app(application)