title: Github: readonly access to a private repo
body: <p>I am developing some private projects on Github, and I would like to add nightly cronjobs to my deployments servers to pull the latest version from github. I am currently doing this by generating keypairs on every deployment server and adding the public key to the github project as 'Deployment key'. </p>
  
  <p>However, I recently found out that these deployment keys actually do have write access to the project. Hence, every of the server administrators could potentially start editing. Furthermore I can add every deployment key to only one repository, whereas I would like to be able to deploy multiple repositories on one and the same deployment server.</p>
  
  <p>Is there a way to provide read-only access for private repositories to selected users on Github?</p>