错误信息：
$ git push origin master
ssh: Could not resolve hostname bitbucket.org: Name or service not known
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
解决方法：
$ vi /etc/resolv.conf # 修改为
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN nameserver 114.114.114.114 8.8.8.8
114.114.114.114 是腾讯DNS Server， 8.8.8.8 是Google DNS Server。