Comply with Golang semantic import versioning (#630)

* Code: compatible with semantic import versioning

* Tools & Docs: compatible with semantic import versioning

* Clean go.mod & go.sum

pkg/email/init.go

@@ -1,9 +1,10 @@
 package email
 
 import (
-	model "github.com/HFO4/cloudreve/models"
-	"github.com/HFO4/cloudreve/pkg/util"
 	"sync"
+
+	model "github.com/cloudreve/Cloudreve/v3/models"
+	"github.com/cloudreve/Cloudreve/v3/pkg/util"
 )
 
 // Client 默认的邮件发送客户端