Updater does not work for GitHub users

[Mr-Pepe]

Trying to test #1, I realized that the updater currently only works for actual GitHub organizations and not for users.

There are two ways of supporting GitHub users.

The CLI argument github_organization could be renamed to github_organization_or_user and the repositories could be retrieved like this:

try:
    repos = Github(github_access_token).get_organization(github_organization_or_user).get_repos()
except UnknownObjectException:
    repos = Github(github_access_token).get_user(github_organization_or_user).get_repos()

However, this only retrieves a user's public repositories and the REST API that backs this specific PyGithub functionality does not provide a way to list private repositories.

The second way is to turn the github_organization argument into an option and doing this:

# Turn `github_organization` into an option

if github_organization:
    repos = Github(github_access_token).get_organization(github_organization).get_repos()
else:
    repos = Github(github_access_token).get_user().get_repos(affiliation="owner")

Not providing a user name for Github(github_access_token).get_user() retrieves the user authenticated by the token. Calling get_repos() on that user retrieves private repositories but also includes all repositories of organizations the user is a member of. This can be controlled by the affiliation parameter of get_repos to only retrieve repositories owned by the user.

I think the second option is preferable.