Attempted to add feature to display when ships are sunk.

Had to restructure JSON object returned by get_shot_results and opponent_turn_results.

Restructured helpers for looking up results.

Revised migration for PlayerShips to include .sunk attribute.

Check if ship sunk via PlayerShips#sunk? #sunk? calls method that returns .sunk if true, otherwise runs check_sunk.

Took forever to get JSON to actually say sunk when sunk.

Attempt to modify OffenseResultsView do display sinking failed. Will work on tomorrow.