Implement "move" of Board

[katzuv]

Board.move should get the pit which was chosen in the last turn, and implement the whole turn (preferably through a couple of methods). The steps are:

• change player from up to down and vice versa
• enable self.player's pits.
• deposit the stones in the pits following the above-mentioned pit (remember to skip the opponent's store and not skip the player's store). This step should be called sowing.
• at the end of turn, check whether the last stone fell in
  • the player's store. If so, grant the player another turn
  • an empty pit. If so, the player captures that piece and any pieces in the pit directly opposite
• call self._game_over_if_needed.
• disable self.player's pits. Maybe this post can help with that.
• change player from up to down and vice versa.

The full rules of Mancala, if needed, can be found here.