Remotes library in DESCRIPTION fail when auth_token needed in gitlab

[overmar]

This is an update of #87 which addressed the issue of an auth_token being needed for github, the same problem is happening in gitlab, and I used the same method (adding the ... to functions) to allow it to be passed through to the download function. But instead of relying on setting the system variable, it looks for the auth_token in the ..., this has been fixed at least for gitlab in #266