chore: refactor the imports (#2406)

core/metric/counter.go

@@ -1,10 +1,9 @@
 package metric
 
 import (
+	prom "github.com/prometheus/client_golang/prometheus"
 	"github.com/zeromicro/go-zero/core/proc"
 	"github.com/zeromicro/go-zero/core/prometheus"
-
-	prom "github.com/prometheus/client_golang/prometheus"
 )
 
 type (

core/metric/counter_test.go

@@ -3,10 +3,9 @@ package metric
 import (
 	"testing"
 
-	"github.com/zeromicro/go-zero/core/prometheus"
-
 	"github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/stretchr/testify/assert"
+	"github.com/zeromicro/go-zero/core/prometheus"
 )
 
 func TestNewCounterVec(t *testing.T) {

core/metric/gauge.go

@@ -1,10 +1,9 @@
 package metric
 
 import (
+	prom "github.com/prometheus/client_golang/prometheus"
 	"github.com/zeromicro/go-zero/core/proc"
 	"github.com/zeromicro/go-zero/core/prometheus"
-
-	prom "github.com/prometheus/client_golang/prometheus"
 )
 
 type (

core/metric/histogram.go

@@ -1,10 +1,9 @@
 package metric
 
 import (
+	prom "github.com/prometheus/client_golang/prometheus"
 	"github.com/zeromicro/go-zero/core/proc"
 	"github.com/zeromicro/go-zero/core/prometheus"
-
-	prom "github.com/prometheus/client_golang/prometheus"
 )
 
 type (