Fixed balance method
Updated balance binary tree so that Node includes parent and balance factor.  Added method updateBalance to recacluate balance on insert
Added tests for parent and updateBalance
Implemented methods for right and left rotations
Added rebalance method and tests, they pass
Finished initial implementation of calendar challenge
Made syntax more pythonic
Add implementation of insertion sort
Add test and run times
Merge pull request #26 from johnshiver/insertion_sort_j

Insertion sort j