Add a unit test for CryptoSeed.

Author: matthewdale

internal/randutil/randutil_test.go

@@ -0,0 +1,16 @@
+package randutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCryptoSeed(t *testing.T) {
+	seeds := make(map[int64]bool)
+	for i := 1; i < 1000000; i++ {
+		s := CryptoSeed()
+		require.False(t, seeds[s], "CryptoSeed returned a duplicate value %d", s)
+		seeds[s] = true
+	}
+}