add week 2 files
Update basic week 2, day 1, dusk lecture scaffold
Add examples of first-class and higher-order functions
Fix indentation in examples
fix details
Fill in forEach example and Add exercises
Fill in forEach example and Add exercises
Update README.md
Update README.md
Add each and for_each
Update Readme and Add implementation of the functions
Add more details to the filter exercise
Change reduce to filter
Add filter
Update README.md
Merge pull request #1 from sf-wdi-15/week_02

add week 2 files