New features

- Add tests to group module #89
- Add redirection when user want to access group he's not in #101
- Add option to leave a group #95
- Refactoring points calculation #97
- User ca now join more than one group #90 #88
- Allow a group to be hidden

- Group enhancements (see #84 #80 #77 #79 #81)
- Refactoring - code cleaning
- Fix issue on last bet page #83
- Clean User profile page #82

- Email reminders - fix problem in url when not logged in to avoid 403 (issue #76)
- Add mespronos_group submodule

- Refactoring ranking management in order to allow groups and domains
- Email reminders

- Enhance betting form
- Add ability to remove bets on a given game
- Add profile page
- Add Docs folder
- Add doc about league
- Allow to archive league from administration dashboard
- Add palmares to profile page

- Add logo to teams
- Add logo to leagues
- New administration dashboard
- Enhance code