Yogit

* Improve help

* Add ability to list your current reviews and see outdated ones with `yogit rv list`
* Dedicated wording when there is no result
* Add "Count: X" statement right after result list
* Show a spinner during request time
* Use bold and emojis to make outputs fancier

* Reinforce `scrum report` command (better error handling)

* Add abilitiy to list pull requests of an organization `yogit pr list --orga TEXT`

* Fix typo in scrum report, thx genygilles

* Fix unauthorized error due to too old PyYAML version