Commit cabal file to the repo to get rid of stack warning

[jhrcek]

Don't merge

This is just temporal branch to get rid of this stack warning before serverless-haskell switches to amazonka 2 and releases a new version to hackage.

Fixing the following warning:

DEPRECATED: The package at Archive from https://github.com/jhrcek/serverless-haskell/archive/bdd5f9ebed171fe23bbdec65392931ba0cbbc896.tar.gz does not include a cabal file.
Instead, it includes an hpack package.yaml file for generating a cabal file.
This usage is deprecated; please see https://github.com/commercialhaskell/stack/issues/5210.
Support for this workflow will be removed in the future.

[jhrcek]

Chances from this PR included in upstream PR seek-oss#189