test ssh connection for github
$ ssh -vT git@github.com > ... > debug1: identity file /Users/you/.ssh/id_rsa type -1 > debug1: identity file /Users/you/.ssh/id_rsa-cert type -1 > debug1: identity file /Users/you/.ssh/id_dsa type -1 > debug1: identity file /Users/you/.ssh/id_dsa-cert type -1 > ... > debug1: Authentications that can continue: publickey > debug1: Next authentication method: publickey > debug1: Trying private key: /Users/you/.ssh/id_rsa > debug1: Trying private key: /Users/you/.ssh/id_dsa > debug1: No more authentication methods to try. > Permission denied (publickey).
Source: docs.github.com