Added Doggo class and Doggo test class.

src/main/java/Doggo.java

@@ -0,0 +1,67 @@
+/* Class representing a Doggo.
+ */
+
+public class Doggo implements Tradable, Domesticatable{
+    private int price;
+    private int happiness;
+
+    public Doggo() {
+        this.price = 5;
+        this.happiness = 10;
+    }
+
+    /**
+     * Returns the sound the Doggo makes.
+     *
+     * @return A String representing the Doggo's sound.
+     */
+    @Override
+    public String sound() { return "Woof!"; }
+
+    /**
+     * Returns the Doggo's price.
+     *
+     * @return An int representing the Doggo's price in dollars.
+     */
+    @Override
+    public int getPrice() { return this.price; }
+
+    /**
+     * Gives a good Doggo a treat.
+     *
+     * @param count An int representing the amount of treats to give.
+     */
+    public void feedTreat(int count) {
+        this.happiness = Math.min(this.happiness + 5 * count, 100);
+        this.price += this.price + count;
+    }
+
+    /**
+     * Punishes the bad Doggo.
+     *
+     * @param harshness An int representing the degree of harshness for punishment.
+     */
+    public void punishment(int harshness) {
+        this.happiness = Math.max(this.happiness - harshness, 0);
+        this.price = Math.max(Math.round(this.price - harshness / 10.0f), 5);
+    }
+
+    /**
+     * Return's the Doggo's happiness rating from 0-100.
+     *
+     * @return An int representing the Doggo's happiness rating.
+     */
+    public int getHappiness() {
+        return this.happiness;
+    }
+
+    /**
+     * Returns a String representing the Doggo.
+     *
+     * @return A String representing Doggo.
+     */
+    @Override
+    public String toString(){
+        return super.toString() + " (Doggo has happiness rating of " + this.happiness + "!) ";
+    }
+}

src/main/java/Trader.java

@@ -96,8 +96,10 @@ public static void main(String[] args) {
         List<Tradable> all_items = Arrays.asList(
                 new Horse(),
                 new Horse(),
-                new Horse()
-                // TODO: Add Tradable objects here!
+                new Horse(),
+                // Add Tradable objects here!
+                new Doggo(),
+                new Doggo()
         );
 
         /* Below, we've created two Traders. Their money, inventory, and

src/test/java/DoggoTest.java

@@ -0,0 +1,42 @@
+/* This file does the testing for Doggo.java.
+ */
+
+import org.junit.*;
+import static org.junit.Assert.*;
+
+public class DoggoTest {
+    Doggo dog;
+
+    @Before
+    public void setUp() throws Exception {
+        dog = new Doggo();
+    }
+
+    @Test(timeout = 50)
+    public void TestSound() {
+        assertEquals("Woof!", dog.sound());
+    }
+
+    @Test(timeout = 50)
+    public void TestGetHappiness() {
+        assertEquals(10, dog.getHappiness());
+    }
+
+    @Test(timeout = 50)
+    public void TestFeedTreat() {
+        dog.feedTreat(8);
+        assertEquals(50, dog.getHappiness());
+    }
+
+    @Test(timeout = 50)
+    public void TestPunishment() {
+        dog.punishment(100);
+        assertEquals(0, dog.getHappiness());
+    }
+
+    @Test(timeout = 50)
+    public void TestGetPrice() {
+        assertEquals(5, dog.getPrice());
+    }
+
+}