Implement go-tuf interop test suite
Implement go-tuf interop test suite

This adds a test to rust-tuf that verifies it can successfully parse the
fuchsia go-tuf fork's TUF 1.0 metadata. Unfortunately due to #225, we
can't correctly parse all the metadata yet, so this patch just ignores
that output for now.

heartsucker/rust-tuf,heartsucker/rust-tuf,heartsucker/rust-tuf