add password manager entry class

src/main/java/PasswordManager.java

@@ -0,0 +1,19 @@
+public class PasswordManager implements PasswordManagerInterface {
+    public static void main(String[] args) {
+        new PasswordManager();
+    }
+
+    public PasswordManager() {
+        System.out.println("Hello World");
+    }
+
+    @Override
+    public void listVaults() {
+
+    }
+
+    @Override
+    public void openVault() {
+
+    }
+}

src/test/java/PasswordManagerTest.java

@@ -0,0 +1,11 @@
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class PasswordManagerTest {
+
+    @Test
+    void constructor() {
+        PasswordManager pm = new PasswordManager();
+    }
+}