feat: add initial MongoDBTest class with a placeholder test method

Author: otaviojava

src/test/java/org/soujava/demos/mongodb/MongoDBTest.java

@@ -0,0 +1,12 @@
+package org.soujava.demos.mongodb;
+
+import org.junit.jupiter.api.Test;
+
+public class MongoDBTest {
+
+
+    @Test
+    void test() {
+
+    }
+}