Hands-on Rust: Example code fails to run without crashing

@herbert

I did find that if if I locked the bracket-terminal version to 0.8.5, the example code, compiles and runs correctly and without panics.

I compared the Cargo.lock in the base directory of the HandOn... repo and the copied example and noticed the bracket-terminal versions were different.

Since I am new to rust, I am still trying to discern why they are different.