[goclidote] Use a transaction per device in RemoveDevicesFromAntidote()

Removing a large array of devices, with thousands of updates inside a
single client.StartTransaction() terribly slow down the request.
Instead, do a transaction commit after processing each item in the
array, still inside a single connection to AntidoteDB.
Signed-off-by: Roger Pueyo Centelles <rpueyo@ac.upc.edu>

goclidote/goclidote.go

@@ -388,10 +388,10 @@ func RemoveDevicesFromAntidote(oldDevices []cnml.DeviceIpv4sGraphserver, Databas
 	errCheck(err, ERROR, "[RemoveDevicesFromAntidote]: Unable to create a new AntidoteDB go client")
 	defer client.Close()
 
-	tx, err := client.StartTransaction()
-	errCheck(err, ERROR, "[RemoveDevicesFromAntidote]: Unable to start a transaction using the go client")
-
 	for _, v := range oldDevices {
+		tx, err := client.StartTransaction()
+		errCheck(err, ERROR, "[RemoveDevicesFromAntidote]: Unable to start a transaction using the go client")
+
 		// Remove the graphserver register from the device-id bucket
 		//fmt.Println(v)
 		bucketName := fmt.Sprintf("device-%d", v.ID)
@@ -494,10 +494,10 @@ func RemoveDevicesFromAntidote(oldDevices []cnml.DeviceIpv4sGraphserver, Databas
 			// Device successfully removed
 			remDevices = append(remDevices, v)
 		}
-	}
 
-	err = tx.Commit()
-	errCheck(err, ERROR, "[AntidoteRemoveRegisterInBucket]: Unable to commit transaction")
+		err = tx.Commit()
+		errCheck(err, ERROR, "[AntidoteRemoveRegisterInBucket]: Unable to commit transaction")
+	}
 
 	return remDevices
 }