unittest: Added test to ItemTest

This tests the price of the item

src/test/java/org/bitbiome/entitiesTest/ItemTest.java

@@ -18,6 +18,7 @@ public class ItemTest {
         item.setDamage("12,5");
         item.changeDoesDamage(true);
         item.setAmount(5);
+        item.setGold(100);
     }
 
     @Test 
@@ -41,4 +42,9 @@ public class ItemTest {
     public void testGetAmount() {
         assumeTrue(item.getAmount() == 5);
     }
+
+    @Test
+    public void testGetGold() {
+        assumeTrue(item.getGold() == 100);
+    }
 }