Merge branch 'develop' of https://github.com/PaddlePaddle/PaddleSpeech into add_new_tacotron2, test=tts

[TTS]fix fastspeech2  multi speaker to static, test=tts

[Doc]rm s2t:augmentation.md,

[CLI] asr, Add Deepspeech2 online and offline model

[ST] beam search with optimality guarantees

[Setup] Synchronize the version

[ASR] Fix some bugs

[Setup]Update version

[doc] fix release_python_package doc

* fix the licence, test=doc

* Update ctc_beam_search_decoder.cpp

* Update ctc_beam_search_decoder.h

* Update ctc_greedy_decoder.cpp

* Update ctc_greedy_decoder.h

* Update decoder_utils.cpp

* Update decoder_utils.h

* Update path_trie.cpp

* Update path_trie.h

* Update scorer.h

* Update scorer.cpp

[install] remove nltk deps

[Setup] fix requirement