Closes #49 - Our specific default rules are applied
Refs #48 - Some tests for calculating the score of a board
Refs #48, #50 - Added functions to resign, pass and get the result of the game,
removed the scoring tests as the scoring functionality is encapsulated in our Game
Refs #48 - Added comment to clarify the score calculation
refs #51 - added actual test to the a_player_can_resign testcase
Merge pull request #51 from augmented-go/additional_functionality_for_backend

Closes #48, #49, #50 - Additional functionality for backend