title: How to avoid add ssh key everytime when push or pull the code
body: <p>I generated the ssh pub key and private key and register pub key to my github.
  And add the private key by using this</p>
  <pre><code>$ eval $(ssh-agent -s)
  $ ssh-add ~/.ssh/id_rsa
  </code></pre>
  <p>But I have to put this command everytime when I push or pull the code.
  I hope to avoid this.</p>