Merge branch 'patch-5' into 'master'

Update README.md

Added a line to the SSH Key Gen section, to ensure that the `before_script` does not prompt for a passphrase.

See merge request !6176

doc/ci/ssh_keys/README.md

@@ -30,7 +30,8 @@ This is the universal solution which works with any type of executor
 ## SSH keys when using the Docker executor
 
 You will first need to create an SSH key pair. For more information, follow the
-instructions to [generate an SSH key](../../ssh/README.md).
+instructions to [generate an SSH key](../../ssh/README.md). Do not add a comment
+to the SSH key, or the `before_script` will prompt for a passphrase.
 
 Then, create a new **Secret Variable** in your project settings on GitLab
 following **Settings > Variables**. As **Key** add the name `SSH_PRIVATE_KEY`