fix import paths for v2 release

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

config/source/memory/memory.go

@@ -6,7 +6,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
-	"github.com/micro/go-micro/config/source"
+	"github.com/micro/go-micro/v2/config/source"
 )
 
 type memory struct {

config/source/memory/options.go

@@ -3,7 +3,7 @@ package memory
 import (
 	"context"
 
-	"github.com/micro/go-micro/config/source"
+	"github.com/micro/go-micro/v2/config/source"
 )
 
 type changeSetKey struct{}

config/source/memory/watcher.go

@@ -1,7 +1,7 @@
 package memory
 
 import (
-	"github.com/micro/go-micro/config/source"
+	"github.com/micro/go-micro/v2/config/source"
 )
 
 type watcher struct {