!39 add system info to CPU install

Merge pull request !39 from Hanshize/master

install/mindspore_cpu_install.md

 # 安装MindSpore
 
-本文档介绍如何在CPU的环境上快速安装MindSpore。
+本文档介绍如何在CPU环境的Ubuntu系统上快速安装MindSpore。
 
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install/mindspore_cpu_install_en.md

 # MindSpore Installation Guide
 
-This document describes how to quickly install MindSpore on a CPU environment.
+This document describes how to quickly install MindSpore on a Ubuntu system with a CPU environment.
 
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