Add `wai-session-redis`
Add `wai-session-redis`

I am an author and maintainer of `wai-redis-session` package

Checklist:
- [x] Meaningful commit message, eg `add my-cool-package` (please not mention `build-constraints.yml`)
- [x] At least 30 minutes have passed since uploading to Hackage
- [x] On your own machine, you have successfully run the following command (find verify-package in the root of this repo):
fpco/stackage,simonmichael/stackage,iand675/stackage,Daniel-Diaz/stackage,jonschoning/stackage,michalkonecny/stackage,mrkkrp/stackage