Missing ipywidgets package in Docker causes intent/slot tutorial to raise ImportError
**Describe the bug**

When running in the NeMo Docker container, the Intent/slot model tutorial errors out due to missing ipywidgets package.

**Steps/Code to reproduce bug**

Running [tutorial notebook](https://github.com/NVIDIA/NeMo/blob/main/tutorials/nlp/Joint_Intent_and_Slot_Classification.ipynb) in the nvcr.io/nvidia/nemo:1.0.0b3 docker container

This line raises an ImportError:
`model = nemo_nlp.models.IntentSlotClassificationModel(config.model, trainer=trainer)`

```
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
/opt/conda/lib/python3.6/site-packages/nemo/collections/common/tokenizers/huggingface/auto_tokenizer.py in __init__(self, pretrained_model_name, vocab_file, mask_token, bos_token, eos_token, pad_token, sep_token, cls_token, unk_token)
    103             else:
--> 104                 self.tokenizer = AUTOTOKENIZER.from_pretrained(pretrained_model_name_or_path=pretrained_model_name)
    105         except Exception as e:

/opt/conda/lib/python3.6/site-packages/transformers/tokenization_auto.py in from_pretrained(cls, pretrained_model_name_or_path, *inputs, **kwargs)
    305         if not isinstance(config, PretrainedConfig):
--> 306             config = AutoConfig.from_pretrained(pretrained_model_name_or_path, **kwargs)
    307 

/opt/conda/lib/python3.6/site-packages/transformers/configuration_auto.py in from_pretrained(cls, pretrained_model_name_or_path, **kwargs)
    332         """
--> 333         config_dict, _ = PretrainedConfig.get_config_dict(pretrained_model_name_or_path, **kwargs)
    334 

/opt/conda/lib/python3.6/site-packages/transformers/configuration_utils.py in get_config_dict(cls, pretrained_model_name_or_path, **kwargs)
    387                 resume_download=resume_download,
--> 388                 local_files_only=local_files_only,
    389             )

/opt/conda/lib/python3.6/site-packages/transformers/file_utils.py in cached_path(url_or_filename, cache_dir, force_download, proxies, resume_download, user_agent, extract_compressed_file, force_extract, local_files_only)
    954             user_agent=user_agent,
--> 955             local_files_only=local_files_only,
    956         )

/opt/conda/lib/python3.6/site-packages/transformers/file_utils.py in get_from_cache(url, cache_dir, force_download, proxies, etag_timeout, resume_download, user_agent, local_files_only)
   1163 
-> 1164             http_get(url_to_download, temp_file, proxies=proxies, resume_size=resume_size, user_agent=user_agent)
   1165 

/opt/conda/lib/python3.6/site-packages/transformers/file_utils.py in http_get(url, temp_file, proxies, resume_size, user_agent)
   1033         desc="Downloading",
-> 1034         disable=bool(logging.get_verbosity() == logging.NOTSET),
   1035     )

/opt/conda/lib/python3.6/site-packages/tqdm/notebook.py in __init__(self, *args, **kwargs)
    231         self.container = self.status_printer(
--> 232             self.fp, total, self.desc, self.ncols)
    233         if display_here:

/opt/conda/lib/python3.6/site-packages/tqdm/notebook.py in status_printer(_, total, desc, ncols)
     96             raise ImportError(
---> 97                 "IProgress not found. Please update jupyter and ipywidgets."
     98                 " See https://ipywidgets.readthedocs.io/en/stable"

ImportError: IProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html

During handling of the above exception, another exception occurred:

ValueError                                Traceback (most recent call last)
<ipython-input-5-676c262478c3> in <module>
      1 # initialize the model
----> 2 model = nemo_nlp.models.IntentSlotClassificationModel(config.model, trainer=trainer)
      3 
      4 
      5 # train

/opt/conda/lib/python3.6/site-packages/nemo/collections/nlp/models/intent_slot_classification/intent_slot_classification_model.py in __init__(self, cfg, trainer)
     62         )
     63 
---> 64         self._setup_tokenizer(cfg.tokenizer)
     65         # init superclass
     66         super().__init__(cfg=cfg, trainer=trainer)

/opt/conda/lib/python3.6/site-packages/nemo/collections/nlp/models/intent_slot_classification/intent_slot_classification_model.py in _setup_tokenizer(self, cfg)
    235             tokenizer_model=cfg.tokenizer_model,
    236             special_tokens=OmegaConf.to_container(cfg.special_tokens) if cfg.special_tokens else None,
--> 237             vocab_file=cfg.vocab_file,
    238         )
    239         self.tokenizer = tokenizer

/opt/conda/lib/python3.6/site-packages/nemo/collections/nlp/modules/common/tokenizer_utils.py in get_tokenizer(tokenizer_name, tokenizer_model, vocab_file, special_tokens)
     71         return CharTokenizer(vocab_file=vocab_file, **special_tokens_dict)
     72 
---> 73     return AutoTokenizer(pretrained_model_name=tokenizer_name, vocab_file=vocab_file, **special_tokens_dict,)

/opt/conda/lib/python3.6/site-packages/nemo/collections/common/tokenizers/huggingface/auto_tokenizer.py in __init__(self, pretrained_model_name, vocab_file, mask_token, bos_token, eos_token, pad_token, sep_token, cls_token, unk_token)
    104                 self.tokenizer = AUTOTOKENIZER.from_pretrained(pretrained_model_name_or_path=pretrained_model_name)
    105         except Exception as e:
--> 106             raise ValueError(f'{pretrained_model_name} is not supported by HuggingFace. {e}')
    107 
    108         special_tokens_dict = {}

ValueError: bert-base-uncased is not supported by HuggingFace. IProgress not found. Please update jupyter and ipywidgets. See https://ipywidgets.readthedocs.io/en/stable/user_install.html


```


**Environment overview (please complete the following information)**

 - Environment location: local machine
 - Method of NeMo install: Docker  



**Additional context**

Fixed by `pip install ipywidgets`