CI infrastructure, dependency updates

[begedin]

Offering this as a PR mainly just to check if I get a reply. Already applied to master branch of my fork.

This adds a workflow action to build and test everything, formats the code, resolves credo and dialyzer issues and updates a bunch of dependencies.

It also includes my other PR, #50

If more information is needed, whoever is in charge of the Repo, please reply and I will gladly add it.