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/cache/memo.go

@@ -1,9 +1,10 @@
 package cache
 
 import (
-	"github.com/HFO4/cloudreve/pkg/util"
 	"sync"
 	"time"
+
+	"github.com/cloudreve/Cloudreve/v3/pkg/util"
 )
 
 // MemoStore 内存存储驱动