Benchmarks in the test

Just wanted to see what kind of performance was going on. Not too shabby.

```
╰─$ go test -bench .
PASS
BenchmarkTinyTo 10000000          218 ns/op
BenchmarkTinyFrom       5000000        380 ns/op
ok      github.com/jesseobrien/tiny-go/src/zackkitzmiller/gotiny  4.880s
```