First round of changes to this lesson.
Update stats and test_stats to new lesson.
Add nose tests
Finish up testing reorg
Move advanced exercise back to end
Introduce nose tests earlier.
Better reference to best practice when introducing nosetests'
Remove work files from repo
put stats.py and test_stats.py back in repo as finished examples.
Start adding git practice - test formatting
Start adding git practice - check more formatting options
Added git practice throughout mean testing
incorporated git practice throughout
Merge pull request #73 from gonuke/rearrange_testing

Rearrange testing