Merge pull request #7 from puiesabu/W3-callbacks

Week 3 exercise: callbacks
Use Person model in rspec
Implement default option
Implement type option for field
Setup coveralls
Update coverall status
Merge pull request #8 from puiesabu/W3-callbacks

Use recursion instead of loop for compiling lambda
Merge pull request #9 from puiesabu/W3-callbacks

Minor fix on calling precompiled callback
Update coveralls setting
Implement #{field}_changed?
Implement #{field}_change
Implement #{field}_was
Implement #{field}_reset
Merge pull request #10 from puiesabu/W2-CRUD

Implement Dirty methods
Implement #reload
Merge pull request #11 from puiesabu/W2-CRUD

Implement #reload
Implement update callback
Implement delete callback
Normalize callbacks and create test data in before block
Implement find callback