Ripping out unneeded Array of Threads

sudoku/brain.rb

@@ -22,15 +22,14 @@ def solvers(blanks)
   end
 
   def guess(board, blanks, state)
-    threads = []
     brain_cells = sorted_cells_with_coords_from(blanks)
     brain_cells.each do |brain_cell, coords|
       brain_cell.size.times do |i|
         board[coords.last][coords.first] = brain_cell[i]
         if state.finished
           return
         else
-          threads << Thread.new do
+          Thread.new do
             think(board, self, state)
           end
         end