Move unfinished exercises
Complete space age exercise
Improve precision on space age calculations
Add gigasecond exercise
Add pythagorean triplet exercise
Add Pascal's Triangle exercise
Add pling-plang-plong problem
Add pride to latest exercises
Clean up test setup in warmups
Add binary search tree warmup
Add binary search tree warmup for #each

This builds on the binary search tree exercise that implements #insert.
Add luhn formula warmup
Add word count exercise
Add kindergarden garden warmup