Multiple SSH Keys settings for different github account

https://medium.com/@trionkidnapper/ssh-keys-with-multiple-github-accounts-c67db56f191e


Host frontend.github.com
 HostName github.com
 IdentityFile ~/.ssh/frontend
Host backend.github.com
 HostName github.com
 IdentityFile ~/.ssh/backend

https://gist.github.com/jexchan/2351996

https://stackoverflow.com/questions/17846529/could-not-open-a-connection-to-your-authentication-agent
