feature to add custom changeset && call hooks

[mighty-potato]

I really like the concept but It will be truly customizable if we able to add our own changeset to each function and hooks before && after for each call. I really would love to help to implement this feature but since my macro in elixir skill is still very low. and again thank you the great one for this awesome lib.

[rzane]

Sounds like a good idea. I don't have much time to dedicate to this project right now, but if you want to send a PR, that would be awesome!