4gewinnt: added getFreePlace method

src/main/java/de/tims/viergewinnt/ai/Logic.java

@@ -58,6 +58,10 @@ public class Logic {
 		return this.player2Score;
 	}
 	
+	public int getFreePlace(int column) {
+		return this.getBoardSize();
+	}
+	
 	public int playChip(int column) {
 		
 		//add board update

src/test/java/de/tims/viergewinnt/ai/LogicTest.java

@@ -187,6 +187,11 @@ class LogicTest {
 		assertEquals(10, testObj.getPlayer1Score());
 	}
 	
+	@Test
+	void getFreePlaceTest() {
+		assertEquals(testObj.getBoardSize(), testObj.getFreePlace(0));
+	}
+	
 	private static Stream<Arguments> playfieldResults() {
 		int[][] playfield1 = {{0, 0, 0, 0, 0, 0}, 
 				   			  {0, 0, 0, 0, 0, 0},