detect rust & cargo.

go/detect/detect.go

		"test": "bundle exec rake test"}, rubyRails},
	&Project{"ruby/rake", Commands{"run": "rake", "test": "rake test"}, rubyRake},
	&Project{"ruby/default", Commands{"run": "ruby {file}"}, rubyDefault},
	&Project{"rust/cargo", Commands{"build": "cargo build", "run": "cargo run", "test": "cargo test"}, rustCargo},
	&Project{"rust/default", Commands{"run": "rustc {file} && ./$(basename {file} .rs)"}, rustDefault},
	&Project{"make", Commands{"run": "make", "test": "make test"}, makeDefault},
	&Project{"procfile", Commands{}, procfileDefault},
}
func rubyDefault(file string) bool {
	return matchingFileOrDir(file, "*.rb")
}
func rustCargo(file string) bool {
	return hasFile(file, "Cargo.toml")
}
func rustDefault(file string) bool {
	return matchingFileOrDir(file, "*.rs")
}

go/examples/hello.rs

fn main() {
	println!("Hello, World!")
}