Add resource path base to DownloaderFactory

Author: XiangRongLin

extractor/src/test/java/org/schabi/newpipe/downloader/DownloaderFactory.java

@@ -6,6 +6,8 @@
 
 public class DownloaderFactory {
 
+    public final static String RESOURCE_PATH = "src/test/resources/org/schabi/newpipe/extractor/";
+
     private final static DownloaderType DEFAULT_DOWNLOADER = DownloaderType.REAL;
 
     public Downloader getDownloader(String path) throws IOException {

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

@@ -43,7 +43,7 @@ public class YoutubeMixPlaylistExtractorTest {
     private static final String VIDEO_ID = "_AzeUSL9lZc";
     private static final String VIDEO_TITLE =
             "Most Beautiful And Emotional  Piano: Anime Music Shigatsu wa Kimi no Uso OST IMO";
-    private static final String RESOURCE_PATH = "src/test/resources/org/schabi/newpipe/extractor/services/youtube/mix/";
+    private static final String RESOURCE_PATH = DownloaderFactory.RESOURCE_PATH + "services/youtube/mix/";
     private static final Map<String, String> dummyCookie
             = Collections.singletonMap(YoutubeMixPlaylistExtractor.COOKIE_NAME, "whatever");