Update app.py

app.py

@@ -12,7 +12,7 @@ separator = Separator('spleeter:2stems')
 def extract_stems(audio):
     
     # initiate a folder for splitted files
-    foldername = str(random2.randrange(100000000))
+    foldername = "./output/" + str(random2.randrange(100000000))
 
     # Separate audio input. Synchronous is true to wait for the end of split before going further
     separator.separate_to_file(audio, foldername, filename_format= foldername + "/{instrument}.wav", synchronous=True)