Getting started with Spock
Spock spec for SudokuGrid
more groovy goodness
dupe possibility list on get
spock test for remove
spock test for place given
spock test for place conjecture
eliminate possibility should return new grid and leave original one intact
spock test for propagation and bug fix found when testing
spock test for failing conjecture
fixed test for when mremoving possibility creates a new copy of the grid
spock test and code for isSolution