Add Close to Conn interface

tracker/conn.go

@@ -68,6 +68,8 @@ type Pool interface {
 // Conn represents a connection to the data store that can be used
 // to make reads/writes.
 type Conn interface {
+	Close() error
+
 	// Torrent interactions
 	FindTorrent(infohash string) (*models.Torrent, error)
 	PutTorrent(t *models.Torrent) error

tracker/memory/conn.go

@@ -17,6 +17,10 @@ type Conn struct {
 	*Pool
 }
 
+func (c *Conn) Close() error {
+	return nil
+}
+
 func (c *Conn) FindUser(passkey string) (*models.User, error) {
 	c.usersM.RLock()
 	defer c.usersM.RUnlock()