cannot import name 'CONFIG_MAPPING' from 'transformers' (unknown location)
trying using the Run_MLM.py script but got an error in importing modules
I installed the transformers package from the source 
```
!git clone https://github.com/huggingface/transformers.git
%cd transformers
!pip install -e .
!pip install -r 'examples/pytorch/language-modeling/requirements.txt
```
any solutions ?
thanks in advance
