centos 系统编译安装pypy5.1 过程
系统自带python2.7.5，gcc4.8.5
记录下centos安装pypy5.1遇到的一些软件的安装：
http://pypy.readthedocs.io/en/latest/build.html#install-build-time-dependencies
sudo yum install openssl-devel
sudo yum install libffi-devel
sudo yum install ncurses-devel
sudo yum install expat-devel
sudo yum install bzip2-devel
sudo yum install python-devel
sudo yum install gdbm-devel
sudo yum install sqlite-devel
sudo yum install tk-devel
下载安装：
zlib-1.2.8.tar.gz
编译安装：
make
sudo make install