Error while import Models
If I run following code:
`punctuation_model = PunctuationCapitalizationModel.from_pretrained("punctuation_en_bert")`
 I get this error:

```
ConfigAttributeError                      Traceback (most recent call last)
<ipython-input-2-e68f34283879> in <module>()
     15 import time
     16 translate_model = MTEncDecModel.from_pretrained("nmt_de_en_transformer12x2")
---> 17 punctuation_model = PunctuationCapitalizationModel.from_pretrained("punctuation_en_bert")
     18 qa_model = QAModel.from_pretrained("qa_squadv1.1_bertbase")
     19 #nmt_model = nemo_nlp.models.MTEncDecModel.from_pretrained(model_name='nmt_ru_en_transformer6x6').cuda()

14 frames
/usr/local/lib/python3.7/dist-packages/omegaconf/dictconfig.py in _get_node(self, key, validate_access, throw_on_missing_value, throw_on_missing_key)
    468         if value is None:
    469             if throw_on_missing_key:
--> 470                 raise ConfigKeyError(f"Missing key {key}")
    471         elif throw_on_missing_value and value._is_missing():
    472             raise MissingMandatoryValue("Missing mandatory value")

ConfigAttributeError: Missing key update_node
    full_key: update_node
    object_type=dict
```
It happens since today. Yesterday it worked fine that way
A clear and concise description of what the bug is.

Normally it should just import the models so I am able to use them. Here is my insall code

```
BRANCH = 'v1.0.0'
!python -m pip install git+https://github.com/NVIDIA/NeMo.git@$BRANCH#egg=nemo_toolkit[all]
```
and my imports:

```
import nemo
import nemo.collections.nlp as nemo_nlp
import nemo.collections.tts as nemo_tts
from nemo.collections.nlp.models import MTEncDecModel
import numpy as np
import IPython.display as ipd
from IPython.display import Audio 
from IPython.core.display import display
from nemo.collections.nlp.models import PunctuationCapitalizationModel
from nemo.collections.nlp.models import QAModel
from nemo.collections.nlp.models import TokenClassificationModel
```
It is executed on a Google Collab with 14 GB of VRAM
