Increased time in summary test

max_age was set to 1ms which was too short for testing and the
quantiles would have expired for the metric assertion in
which there were supposed to have not expired.

Now it is set to 1s and then it waits 2s for the quantiles
to expire.

metrics_test.go

@@ -284,7 +284,7 @@ func Test_SummaryWithSpecifiedMaxAge(t *testing.T) {
 	summaryHelp := "Uses default value for max age"
 
 	var metrics struct {
-		Summary func() prometheus.Summary `name:"without_max_age" help:"Uses default value for max age" max_age:"1ms"`
+		Summary func() prometheus.Summary `name:"without_max_age" help:"Uses default value for max age" max_age:"1s"`
 	}
 
 	err := gotoprom.Init(&metrics, "test")
@@ -308,7 +308,7 @@ func Test_SummaryWithSpecifiedMaxAge(t *testing.T) {
 	err = testutil.GatherAndCompare(prometheus.DefaultGatherer, strings.NewReader(expectedUnexpired), "test_without_max_age")
 	assert.NoError(t, err)
 
-	time.Sleep(time.Millisecond)
+	time.Sleep(time.Second * 2)
 
 	mfs, err := prometheus.DefaultGatherer.Gather()
 	assert.NoError(t, err)