v3 refactor (#1868)

* Move to v3

Co-authored-by: Ben Toogood <bentoogood@gmail.com>

config/source/env/env.go

@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/imdario/mergo"
-	"github.com/micro/go-micro/v2/config/source"
+	"github.com/micro/go-micro/v3/config/source"
 )
 
 var (

config/source/env/env_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/micro/go-micro/v2/config/source"
+	"github.com/micro/go-micro/v3/config/source"
 )
 
 func TestEnv_Read(t *testing.T) {

config/source/env/options.go

@@ -5,7 +5,7 @@ import (
 
 	"strings"
 
-	"github.com/micro/go-micro/v2/config/source"
+	"github.com/micro/go-micro/v3/config/source"
 )
 
 type strippedPrefixKey struct{}

config/source/env/watcher.go

@@ -1,7 +1,7 @@
 package env
 
 import (
-	"github.com/micro/go-micro/v2/config/source"
+	"github.com/micro/go-micro/v3/config/source"
 )
 
 type watcher struct {