TypeError: sequence item 0: expected str instance, NBProgressBar found
# 🐛 Bug

## Information

Model I am using (Bert, XLNet ...): bert-base-multilingual-cased

Language I am using the model on (English, Chinese ...): German

The problem arises when using:
* [X] the official example scripts: (give details below)
* [ ] my own modified scripts: (give details below)

The tasks I am working on is:
* [X] an official GLUE/SQUaD task: NER
* [ ] my own task or dataset: (give details below)

## To reproduce

Steps to reproduce the behavior:

1. Google Colab Notebook
2. Run: `!python3 run_tf_ner.py --data_dir ./data --model_type bert --labels labels.txt --model_name_or_path bert-base-multilingual-cased --output_dir germeval-model --max_seq_length 128 --num_train_epochs 3 --per_device_train_batch_size 32 --save_steps 750 --seed 1 --do_train --do_eval --do_predict`
3.
```
I0330 12:15:45.104261 140536926144384 modeling_tf_utils.py:388] loading weights file germeval-model/tf_model.h5
I0330 12:15:46.316838 140536926144384 modeling_tf_utils.py:428] Layers of TFBertForTokenClassification not initialized from pretrained model: ['dropout_75']
I0330 12:15:46.317042 140536926144384 modeling_tf_utils.py:432] Layers from pretrained model not used in TFBertForTokenClassification: ['dropout_37']
I0330 12:15:46.317251 140536926144384 run_tf_ner.py:420] Loading features from cached file ./data/cached_dev_bert-base-multilingual-cased_128.tf_record
I0330 12:15:46.483210 140536926144384 run_tf_ner.py:318] ***** Running evaluation *****
I0330 12:15:46.483375 140536926144384 run_tf_ner.py:319]   Num examples = 2200
I0330 12:15:46.483478 140536926144384 run_tf_ner.py:320]   Batch size = 8
Traceback (most recent call last):
  File "run_tf_ner.py", line 644, in <module>
    app.run(main)
  File "/usr/local/lib/python3.6/dist-packages/absl/app.py", line 299, in run
    _run_main(main, args)
  File "/usr/local/lib/python3.6/dist-packages/absl/app.py", line 250, in _run_main
    sys.exit(main(argv))
  File "run_tf_ner.py", line 579, in main
    args, strategy, model, tokenizer, labels, pad_token_label_id, mode="dev"
  File "run_tf_ner.py", line 322, in evaluate
    for eval_features, eval_labels in eval_iterator:
  File "/usr/local/lib/python3.6/dist-packages/fastprogress/fastprogress.py", line 39, in __iter__
    if self.total != 0: self.update(0)
  File "/usr/local/lib/python3.6/dist-packages/fastprogress/fastprogress.py", line 56, in update
    self.update_bar(0)
  File "/usr/local/lib/python3.6/dist-packages/fastprogress/fastprogress.py", line 76, in update_bar
    else: self.on_update(val, f'{100 * val/self.total:.2f}% [{val}/{self.total} {elapsed_t}<{remaining_t}{end}]')
  File "/usr/local/lib/python3.6/dist-packages/fastprogress/fastprogress.py", line 126, in on_update
    elif self.parent is not None: self.parent.show()
  File "/usr/local/lib/python3.6/dist-packages/fastprogress/fastprogress.py", line 167, in show
    self.html_code = '\n'.join([getattr(self.inner_dict[n], 'progress', self.inner_dict[n]) for n in to_show])
TypeError: sequence item 0: expected str instance, NBProgressBar found
```

## Expected behavior

Evaluation of test.txt 

## Environment info

     
- `transformers` version: 2.6.0
- Platform: Google  Colab
- Python version: 3.6
- PyTorch version (GPU?): -
- Tensorflow version (GPU?): 2.2.0rc1
- Using GPU in script?: -
- Using distributed or parallel set-up in script?: using example setup

Whats also strange, the PyTorch version list the labels as text, e.g: "B-ORG, I-LOC, [...] in the Model Config Ouput but the TF-version list them like this bellow. Is this okay?

```
"id2label": {
    "0": "LABEL_0",
    "1": "LABEL_1",
    "2": "LABEL_2",
    "3": "LABEL_3",
    "4": "LABEL_4",
    "5": "LABEL_5",
    "6": "LABEL_6",
    "7": "LABEL_7",
    "8": "LABEL_8",
    "9": "LABEL_9",
    "10": "LABEL_10",
    "11": "LABEL_11",
    "12": "LABEL_12",
    "13": "LABEL_13",
    "14": "LABEL_14",
    "15": "LABEL_15",
    "16": "LABEL_16",
    "17": "LABEL_17",
    "18": "LABEL_18",
    "19": "LABEL_19",
    "20": "LABEL_20",
    "21": "LABEL_21",
    "22": "LABEL_22",
    "23": "LABEL_23",
    "24": "LABEL_24",
    "25": "LABEL_25"
```<|||||>Any update or fix for this?<|||||>Got it working - the parent progress bar is not needed for evalute/predict as there is a single iteration. 

In run_tf_ner.py I changed:

eval_iterator = progress_bar(eval_dataset, total=num_eval_steps,parent=master, display=args["n_device"] > 1)

to 

eval_iterator = progress_bar(eval_dataset, total=num_eval_steps, display=args["n_device"] > 1)

and commented out

master = master_bar(range(1))<|||||>This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.
