run: don't supply token if it isn't set
Use -b to force rebuild package and fix arg passing
Improve CLI args handling

- Use jopt to parse options
- Check arguments (REPO)

Usage:

github [-h] [-t TOKEN] REPO
- -h: Help
- TOKEN: Optional GitHub token
- REPO: username/password
Ignore code/
Add libs target
Update repo validity check
Merge branch 'master' of github.com:pschmitt/github-contributions-visualisation