Handle GitHub PAT authorization — get_git

Handle things whether or not a GitHub PAT is supplied.

Usage,

get_git_auth(
  git_pat = NULL,
  git_username = "PersonalAccessToken",
  quiet = FALSE
)

Arguments

git_pat: If private repositories are to be retrieved, a github personal access token needs to be supplied. If none is supplied, then this will attempt to grab from a git pat set in the environment with usethis::create_github_token().
git_username: Optional, can include username for credentials.
quiet: Use TRUE if you don't want the warning about no GitHub credentials.

Authorization argument to supply to curl OR a blank string if no authorization is found or supplied.