update yolo README version. (#2160)

PaddleCV/yolov3/README.md

@@ -12,7 +12,7 @@
 
 ## Installation
 
-Running sample code in this directory requires PaddelPaddle Fluid v.1.4 and later. If the PaddlePaddle on your device is lower than this version, please follow the instructions in [installation document](http://www.paddlepaddle.org/documentation/docs/en/1.4/beginners_guide/install/index_en.html) and make an update.
+Running sample code in this directory requires PaddelPaddle Fluid v.1.5 and later. If the PaddlePaddle on your device is lower than this version, please follow the instructions in [installation document](http://www.paddlepaddle.org/documentation/docs/en/1.4/beginners_guide/install/index_en.html) and make an update.
 
 ## Introduction
 

PaddleCV/yolov3/README_cn.md

@@ -12,7 +12,7 @@
 
 ## 安装
 
-在当前目录下运行样例代码需要PadddlePaddle Fluid的v.1.4或以上的版本。如果你的运行环境中的PaddlePaddle低于此版本，请根据[安装文档](http://paddlepaddle.org/documentation/docs/zh/1.4/beginners_guide/install/index_cn.html)中的说明来更新PaddlePaddle。
+在当前目录下运行样例代码需要PadddlePaddle Fluid的v.1.5或以上的版本。如果你的运行环境中的PaddlePaddle低于此版本，请根据[安装文档](http://paddlepaddle.org/documentation/docs/zh/1.4/beginners_guide/install/index_cn.html)中的说明来更新PaddlePaddle。
 
 ## 简介