Ben

As the title says, I'm wondering what people think about introducing some exercises to rustlings that cover some useful or commonly used Rust crates. So for example, I've been looking...

Firstly, I want to say that I've been really impressed with rustlings. This is my first foray into Rust programming and I've really enjoyed running through the exercises over the...

Based on my suggestion in this [issue](https://github.com/rust-lang/rustlings/issues/1481), I've added support for exercises that rely on crates. I've also added a simple mockall exercise as an example (I'm happy to add...