错误：No module named 'fabric.api'，原因---fabric（2.0新特性）
https://www.cnblogs.com/anthony-wang0228/articles/12504870.html
python三大神器之fabric（2.0新特性）
https://www.cnblogs.com/shenh/p/10060149.html
No module named 'fabric.api'
http://www.mamicode.com/info-detail-2541641.html
https://blog.csdn.net/Tiger_lin1/article/details/84316026
Fabric SSH链接时关于找不到主机的问题
https://www.cnblogs.com/fanjp666888/p/10844643.html
将env.hosts = ['192.168.1.1] 改成env.hosts_string = '192.168.1.1'即可解决单台机器的连接问题.
fabric 远程调用的利器
https://www.jianshu.com/p/46fe090b97f1
Welcome to Fabric’s documentation!
https://docs.fabfile.org/en/2.1/index.html
Linux报错：bash: pip: command not found
https://www.cnblogs.com/wujf-myblog/p/9644278.html
dnspython>=1.15, but you'll have dnspython 1.12.0 which is incompatible
