Add class 6 exercises
Fix class 6 exerise 3
Fix class 6 exerise 2
Improve assignments for class 6
Add executable bit to all class 6 exercises
Tweak class 6 exercise 4
Merge branch 'master' of https://github.com/codefellows/sea-c17-ruby
Tweak to class 6 exercises
fix input validation
Merge branch 'master' of https://github.com/codefellows/sea-c17-ruby
Tweak to class 6 exercise 5
Merge branch 'master' of https://github.com/codefellows/sea-c17-ruby
Finish homework for Class 6