Add vendor folder to git

vendor/github.com/coreos/pkg/timeutil/backoff.go

@@ -0,0 +1,15 @@
+package timeutil
+
+import (
+	"time"
+)
+
+func ExpBackoff(prev, max time.Duration) time.Duration {
+	if prev == 0 {
+		return time.Second
+	}
+	if prev > max/2 {
+		return max
+	}
+	return 2 * prev
+}

vendor/github.com/coreos/pkg/timeutil/backoff_test.go

@@ -0,0 +1,52 @@
+package timeutil
+
+import (
+	"testing"
+	"time"
+)
+
+func TestExpBackoff(t *testing.T) {
+	tests := []struct {
+		prev time.Duration
+		max  time.Duration
+		want time.Duration
+	}{
+		{
+			prev: time.Duration(0),
+			max:  time.Minute,
+			want: time.Second,
+		},
+		{
+			prev: time.Second,
+			max:  time.Minute,
+			want: 2 * time.Second,
+		},
+		{
+			prev: 16 * time.Second,
+			max:  time.Minute,
+			want: 32 * time.Second,
+		},
+		{
+			prev: 32 * time.Second,
+			max:  time.Minute,
+			want: time.Minute,
+		},
+		{
+			prev: time.Minute,
+			max:  time.Minute,
+			want: time.Minute,
+		},
+		{
+			prev: 2 * time.Minute,
+			max:  time.Minute,
+			want: time.Minute,
+		},
+	}
+
+	for i, tt := range tests {
+		got := ExpBackoff(tt.prev, tt.max)
+		if tt.want != got {
+			t.Errorf("case %d: want=%v got=%v", i, tt.want, got)
+		}
+	}
+}