Add YearCheck.stuff to code repo; reworded compiler section
Merge branch 'master' of https://github.com/cs61bl/labs
Updated README with homework schedule; made progress on lab6

To Do:
1. Change all the isOK methods to be void and throw exceptions rather than returning booleans.
2. Change the JUnit tests to check for Exceptions (Expected Exception Test).
Merge branch 'master' of https://github.com/cs61bl/labs