Re-word instructions for class2 exercise 3
Remove class4 git_config
Fix exercise name
Merge branch 'master' of https://github.com/codefellows/sea-c21-ruby

I did a "git pull upstream master" to sync local with instructors Project
Tweak branching example
Improve class4 exercises
Tweak TIP
Homework Class 4 exercise 4 partial
changes from git pull upstream master
Solved homework Class 4 exercise 4 and exercise 5