createAdmin = function(username, password, callback) {
    var url = '/_config/admins/' + username;
    var req = {
        type: 'PUT',
        url: url,
        data: JSON.stringify(password),
        processData: false,
        contentType: 'application/json'
    };
    db.request(req, callback);
}
Create a new user in the admin database.

@name createAdmin(username, password, callback)
@param {String} username
@param {String} password
@param {Function} callback
@api private