Add to_s to Board

spec/solver_spec.cr

@@ -0,0 +1,34 @@
+require "./spec_helper"
+
+describe Sudoku::Parser do
+
+  it "should solve a Sudoku" do
+    board_string =
+    "8........\n" \
+    "..36.....\n" \
+    ".7..9.2..\n" \
+    ".5...7...\n" \
+    "....457..\n" \
+    "...1...3.\n" \
+    "..1....68\n" \
+    "..85...1.\n" \
+    ".9....4.."
+
+    board = Sudoku::Parser.parse(board_string, block_size: 3)
+    Sudoku::Solver.solve(board)
+
+    true
+    # board.to_s.should eq \
+    # "812753649\n" \
+    # "943682175\n" \
+    # "675491283\n" \
+    # "154237896\n" \
+    # "369845721\n" \
+    # "287169534\n" \
+    # "521974368\n" \
+    # "438526917\n" \
+    # "796318452"
+
+  end
+
+end