Merge branch 'dev' of github.com:mozilla/TTS into dev

extract_features.py

@@ -69,7 +69,7 @@ if __name__ == "__main__":
             linear = ap.spectrogram(x.astype('float32')).astype('float32')
             linear_len = linear.shape[1]
             np.save(linear_path, linear, allow_pickle=False)
-            output.insert(2, linear_path+".npy")
+            output.insert(3, linear_path+".npy")
             assert mel_len == linear_len
         if args.process_audio:
             audio_file = file_name + "_audio"