[BUG] Notification test buttons non-functional

[LukeBoland]

The test buttons for Slack/Discord notifications and hc.io do not do anything. The server returns Internal server error 500.

To Reproduce

1. Set up Docker container with Discord webhook in the variables
2. Start the container and open the web interface
3. Go to 'Settings'
4. Click on 'Notifications'
5. Click 'Test Notifications'

• nothing happens - (SpeedTest-Tracker does successfully use this webhook to notify of scheduled tests - only the test functionality seems to be broken)

-or- 4. Click on healthchecks.io 5. Set up hc.io information and enable hc.io with checkbox 6. Click 'Save' 7. Click the 'Start', 'Success' or 'Failure' button

• nothing happens - (SpeedTest-Tracker does not successfully use this webhook to notify of scheduled tests - hc.io records no attempt at communication)

Expected behavior

1. A test message sent to the Discord webhook -or- a test ping sent to hc.io
2. Feedback saying whether the test has been sent successfully or not

Errors From the developer console in Firefox: Failed to load resource: the server responded with a status of 500 (Internal Server Error) - api/settings/test-healthchecks/success?token=undefined app.js?v=1-12-0:4141 Uncaught (in promise) Error: Request failed with status code 500 at createError (app.js?v=1-12-0:4141:15) at settle (app.js?v=1-12-0:4416:12) at XMLHttpRequest.handleLoad (app.js?v=1-12-0:3608:7)

Content of api/settings/test-healthchecks/success?token=undefined: Illuminate\Contracts\Container\BindingResolutionException Target class [IntegrationsController] does not exist.

Context Docker container Version: 1.12.0 Running on UnRAID