first shot
Update README.md
more details on arguments with default values
Allow students to use return
Merge pull request #7 from lewagon/exo-ruby-block-improvement

more details on arguments with default values
Allow for x = x + 1
Merge branch 'master' of github.com:lewagon/promo-4-challenges
finishing guidelines
Merge branch 'guidelines_2'
first shot
small improvements
final guidelines
Merge pull request #9 from lewagon/guidelines_ruby_iterators

Guidelines ruby iterators
Update README.md
Update TEACHERS.md
Update TEACHERS.md
typos
typos
typos
teachers guidelines