added metrics

Change-Id: I7727bd43911339f48e2d096f8bb43729eb65b3ad

vendor/github.com/prometheus/procfs/stat_test.go

@@ -0,0 +1,14 @@
+package procfs
+
+import "testing"
+
+func TestStat(t *testing.T) {
+	s, err := FS("fixtures").NewStat()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if want, have := int64(1418183276), s.BootTime; want != have {
+		t.Errorf("want boot time %d, have %d", want, have)
+	}
+}