Adds an extremely basic initial test to ensure that we are able to
connect to a YubiKey.
The test is marked `#[ignore]` in the hope that we can eventually start
adding tests which run in CI, e.g. against a mock card.
This also includes a fix for calculating the APDU size, since the ones
we were sending originally were overly long.
- Adds initial `Cargo.toml` (and `Cargo.lock` to `.gitignore`)
- Deletes `tool` (it seems hard to `corrode`)
- Moves `lib/tests` => `tests` (we should figure out how to translate them)
- Moves `lib` => `src` to match Rust conventions
- Renames `lib/ykpiv.rs` => `src/lib.rs` to match Rust conventions
- Adds copyright from `ykpiv.h` to the top of all `*.rs` files
Tony Arcieri