Username, Full Name, Email Address, 'GitHub' Username of the
Current User
c(person(given = "Gábor",
                    family = "Csárdi", 
                    email = "csardi.gabor@gmail.com", 
                    role = c("aut", "cre")),
            person(given = "Maëlle",
                   family = "Salmon",
                    role = "ctb"))
Look up the username and full name of the current user,
    the current user's email address and 'GitHub' username,
    using various sources of system and configuration information.
Gábor Csárdi [aut, cre],
  Maëlle Salmon [ctb]