Add explanations to broken tests

Author: XiangRongLin

extractor/src/test/java/org/schabi/newpipe/extractor/services/peertube/PeertubeStreamExtractorTest.java

@@ -96,7 +96,7 @@ public void testGetLanguageInformation() throws ParsingException {
         @Override public int expectedStreamSegmentsCount() { return 0; }
     }
 
-    @Ignore("TODO fix")
+    @Ignore("Test broken, SSL problem")
     public static class AgeRestricted extends DefaultStreamExtractorTest {
         private static final String ID = "dbd8e5e1-c527-49b6-b70c-89101dbb9c08";
         private static final String INSTANCE = "https://nocensoring.net";

extractor/src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudPlaylistExtractorTest.java

@@ -362,7 +362,7 @@ public void testRelatedItems() throws Exception {
         }
 
         @Test
-        @Ignore("TODO fix")
+        @Ignore("Test broken? Playlist has 2 entries, each page has 1 entry meaning it has 2 pages.")
         public void testMoreRelatedItems() throws Exception {
             try {
                 defaultTestMoreItems(extractor);

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubePlaylistExtractorTest.java

@@ -59,7 +59,7 @@ public void nonExistentFetch() throws Exception {
         }
 
         @Test(expected = ContentNotAvailableException.class)
-        @Ignore("TODO fix")
+        @Ignore("Broken, now invalid playlists redirect to youtube homepage")
         public void invalidId() throws Exception {
             final PlaylistExtractor extractor =
                     YouTube.getPlaylistExtractor("https://www.youtube.com/playlist?list=INVALID_ID");

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/stream/YoutubeStreamExtractorControversialTest.java

@@ -21,7 +21,7 @@
 /**
  * Test for {@link YoutubeStreamLinkHandlerFactory}
  */
-@Ignore("Video is not available anymore")
+@Ignore("Video is not available in specific countries. Someone else has to generate mocks")
 public class YoutubeStreamExtractorControversialTest extends DefaultStreamExtractorTest {
     private static final String RESOURCE_PATH = DownloaderFactory.RESOURCE_PATH + "services/youtube/extractor/stream/";
     private static final String ID = "T4XJQO3qol8";

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/stream/YoutubeStreamExtractorDefaultTest.java

@@ -160,7 +160,7 @@ public void testDescription() throws Exception {
 
     }
 
-    @Ignore("TODO fix")
+    @Ignore("Test broken, video was made private")
     public static class RatingsDisabledTest extends DefaultStreamExtractorTest {
         private static final String ID = "HRKu0cvrr_o";
         private static final int TIMESTAMP = 17;