Auto merge of #3842 - pwoolcoc:add-pijul-vcs-support, r=alexcrichton

Add Pijul support to Cargo

[Pijul](https://pijul.org) is a version control system written in Rust. This commit adds the ability to create a cargo project using pijul as the vcs for the project.

To use it, run `cargo new my-awesome-project --vcs=pijul`