Merge pull request #669 from prometheus-community/superq/0.11.1

Pick fixes into release-0.11

Author: SuperQ

collector/pg_stat_bgwriter.go

@@ -126,8 +126,8 @@ func (PGStatBGWriterCollector) Update(ctx context.Context, server *server, ch ch
 
 	var cpt int
 	var cpr int
-	var cpwt int
-	var cpst int
+	var cpwt float64
+	var cpst float64
 	var bcp int
 	var bc int
 	var mwc int