Automate unit tests

[lemastero]

Hello,
In test directory there are golden tests, but there is no code that actually illustrate how to run them.
Since this repo works as example how to build backend, it would be nice to have unit tests encoded in Haskell.

[jespercockx]

I'm honored that this repository serves as an example of how to build a backend but honestly it is just a side project that is currently on hiatus. I would love to have some kind of proper test setup for it though, preferably using tasty-golden or a similar library.