Test and benchmark several implementations of the fibonacci numbers in Go
$ GOMAXPROCS=1 go test . -bench=. -benchmem
BenchmarkFiboRecursive 3000000 471 ns/op 0 B/op 0 allocs/op
BenchmarkFiboClosure 20000000 84.7 ns/op 48 B/op 3 allocs/op
BenchmarkFiboConcurrent 2000000 933 ns/op 192 B/op 1 allocs/op