gopherjs test always fails with deadlock

Create a sample test that does nothing

```
package tmp

import (
	"testing"
)

func Test(t *testing.T) {
}
```
run gopherjs test and though the test is marked as passing, the run fails

```
=== RUN   Test
--- PASS: Test (0.00s)
PASS
fatal error: all goroutines are asleep - deadlock!
FAIL	tmp	0.429s
```
