Thalison

Would be great to have this implemented on the actix-web testing api. For now, a solution is to use another crate [actix-multipart-rfc7578](https://crates.io/crates/actix-multipart-rfc7578). Actix also use this crate to test [their...

facing this same error

Hi @jackkav @filfreire @CurryYangxx @ihexxa, I've pushed this PR that implements a new feature. Any feedback or final touches needed before we can close it out?