Implement blackbox in Golang (#250)

* Initial release

pkg/bbutil/rbio_test.go

@@ -0,0 +1,21 @@
+package bbutil
+
+import (
+	"testing"
+)
+
+func TestRunBashInputOutput(t *testing.T) {
+
+	in := "This is a test of the RBIO system.\n"
+	bin := []byte(in)
+
+	out, err := RunBashInputOutput(bin, "cat")
+	sout := string(out)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if in != sout {
+		t.Errorf("not equal %q %q", in, out)
+	}
+}