[FEATURE REQUEST] Slack Webhooks for Logging

**Is your feature request related to a problem? Please describe.**
I would like to send all the error as well as request logs to a channel in my slack workspace.

**Describe the solution you'd like**
Iris is using golog for logging as of now, we can add custom hooks to the package like logrus has to send the logs to the slack channel whenever a log is created.

**Describe alternatives you've considered**
I have tried configuring logrus with a hook for slack. Then I used `app.Logger().Install()` to use that logrus instance but had no luck.