在centos中yum安装比较新的git
命令很简单：
yum install http://opensource.wandisco.com/centos/6/git/x86_64/wandisco-git-release-6-1.noarch.rpm
yum install git
命令很简单：
yum install http://opensource.wandisco.com/centos/6/git/x86_64/wandisco-git-release-6-1.noarch.rpm
yum install git