add optional argment to cargo test

[Matthew6186]

When I tried to test build result by "cargo test", it failed.

It seems to add "--lib" argument for treat this error

Please check my pull request for detail

My environment (WSL2 in Windows11)

• OS
  • NAME="Ubuntu"
  • VERSION="20.04.5 LTS (Focal Fossa)"
  • ID=ubuntu
  • ID_LIKE=debian
  • PRETTY_NAME="Ubuntu 20.04.5 LTS"
  • VERSION_ID="20.04"
• Rust
  • cargo 1.66.1 (ad779e08b 2023-01-10)

[nlfiedler]

Indeed, that was weird. I'm going to adjust the README a bit to make it clear that this only affects Wiindows. Thanks for your help.