Add test for `rustup show home`. Fixed other test cases.
Add test for `rustup show home`. Fixed other test cases.

nodakai/rustup.rs,rust-lang/rustup,nodakai/rustup.rs,nodakai/rustup.rs,rust-lang/rustup,inejge/rustup.rs,inejge/rustup.rs,rust-lang/rustup,nodakai/rustup.rs,inejge/rustup.rs,inejge/rustup.rs,rust-lang/rustup,inejge/rustup.rs,nodakai/rustup.rs,rust-lang/rustup