Add support for XEP-0118: UserTune

This commit will enable user to communicate
information about music to which user is listening.
This feature is less of a requirement and more like fun to me.
An attempt at solving SMACK-257.

Incase you see any chances of improvement,
please let me know :)

smack-extensions/src/test/java/org/jivesoftware/smackx/usertune/UserTuneElementTest.java

@@ -0,0 +1,74 @@
+/**
+ *
+ * Copyright 2019 Aditya Borikar.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.usertune;
+
+import static org.jivesoftware.smack.test.util.XmlUnitUtils.assertXmlSimilar;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.jivesoftware.smack.parsing.SmackParsingException;
+import org.jivesoftware.smack.test.util.SmackTestSuite;
+import org.jivesoftware.smack.test.util.SmackTestUtil;
+import org.jivesoftware.smack.test.util.SmackTestUtil.XmlPullParserKind;
+import org.jivesoftware.smack.xml.XmlPullParser;
+import org.jivesoftware.smack.xml.XmlPullParserException;
+import org.jivesoftware.smackx.usertune.element.UserTuneElement;
+import org.jivesoftware.smackx.usertune.provider.UserTuneProvider;
+
+import org.junit.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+
+public class UserTuneElementTest extends SmackTestSuite {
+
+    private final String xml = "<tune xmlns='http://jabber.org/protocol/tune'>" +
+            "<artist>Yes</artist>" +
+            "<length>686</length>" +
+            "<rating>8</rating>" +
+            "<source>Yessongs</source>" +
+            "<title>Heart of the Sunrise</title>" +
+            "<track>3</track>" +
+            "<uri>http://www.yesworld.com/lyrics/Fragile.html#9</uri>" +
+            "</tune>";
+
+    @Test
+    public void toXmlTest() throws IOException, XmlPullParserException, SmackParsingException, URISyntaxException {
+
+        URI uri = new URI("http://www.yesworld.com/lyrics/Fragile.html#9");
+
+        UserTuneElement.Builder builder = UserTuneElement.getBuilder();
+        UserTuneElement userTuneElement = builder.setArtist("Yes")
+                .setLength(686)
+                .setRating(8)
+                .setSource("Yessongs")
+                .setTitle("Heart of the Sunrise")
+                .setTrack("3")
+                .setUri(uri)
+                .build();
+        assertXmlSimilar(xml, userTuneElement.toXML().toString());
+    }
+
+    @ParameterizedTest
+    @EnumSource(value = SmackTestUtil.XmlPullParserKind.class)
+    public void userTuneElementProviderTest(XmlPullParserKind parserKind) throws XmlPullParserException, IOException, SmackParsingException {
+        XmlPullParser parser = SmackTestUtil.getParserFor(xml, parserKind);
+        UserTuneElement parsed = UserTuneProvider.INSTANCE.parse(parser);
+        assertXmlSimilar(xml, parsed.toXML().toString());
+    }
+}

smack-extensions/src/test/java/org/jivesoftware/smackx/usertune/UserTuneManagerTest.java

@@ -0,0 +1,58 @@
+/**
+ *
+ * Copyright 2019 Aditya Borikar.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.usertune;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertNotNull;
+import static junit.framework.TestCase.assertTrue;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smack.test.util.SmackTestSuite;
+import org.jivesoftware.smackx.usertune.element.UserTuneElement;
+
+import org.junit.Test;
+
+public class UserTuneManagerTest extends SmackTestSuite{
+
+    @Test
+    public void addMessage() throws URISyntaxException {
+
+        UserTuneElement.Builder builder = UserTuneElement.getBuilder();
+        builder.setArtist("Yes");
+        builder.setLength(686);
+        builder.setRating(8);
+        builder.setSource("Yessongs");
+        builder.setTitle("Heart of the Sunrise");
+        builder.setTrack("3");
+        URI uri = new URI("http://www.yesworld.com/lyrics/Fragile.html#9");
+        builder.setUri(uri);
+        UserTuneElement userTuneElement = builder.build();
+
+        Message message = new Message();
+        message.addExtension(userTuneElement);
+
+        assertTrue(message.hasExtension(UserTuneElement.ELEMENT, UserTuneElement.NAMESPACE));
+        assertTrue(UserTuneElement.hasUserTuneElement(message));
+
+        UserTuneElement element = UserTuneElement.from(message);
+        assertNotNull(element);
+        assertEquals(userTuneElement, element);
+    }
+}