CSP-rs

This is a rust crate to help with making a CSP string to be used with webservers.

Any contributions to improve it are welcome, but I'd like to keep this without any external dependencies.

If someon wants to contribute, but doesn't know what to do: the main 'flaws' that I see with this crate is that it allows for repeating the same CSP directive multiple times, and some invalid Sources for some directives.