Print all args properly in final report

[clubby789]

Fixes #254

When invoked with cargo-bisect-rustc, our args look like ["cargo-bisect-rustc", "--start", ...] However, when invoked with cargo bisect-rustc, our args look like ["/path/to/cargo-bisect-rustc", "bisect-rustc", "--start", ...]

Skip past these initial arguments instead of hardcoding the index