Fix a bug in AbstractGame.next()

AbstractGame.next() would return an incorrect value if it had not already started.

Author: JJ-Atkinson

src/main/java/com/nmerrill/kothcomm/game/games/AbstractGame.java

@@ -56,7 +56,7 @@ public final boolean next(){
             return true;
         }
         step();
-        return finished();
+        return !finished();
     }
 
     public abstract boolean finished();