tictactoe: added test case for checkForWin method

src/test/java/de/tims/tictactoe/GameLogicTest.java

@@ -137,7 +137,11 @@ class GameLogicTest {
 		    			Arguments.of("check win for player 1", true, new char[][] 
 																 {{'x', '-', '-'}, 
 																  {'x', '-', '-'},
-																  {'x', '-', '-'}})
+																  {'x', '-', '-'}}),
+		    			Arguments.of("check win for player 2", true, new char[][] 
+																 {{'o', '-', '-'}, 
+																  {'o', '-', '-'},
+																  {'o', '-', '-'}})
 			    		);
 	 }