Packages not installed after setup.py install, error importing mpu from megatron
**Describe the bug**

After installing using setup.py inside NVIDIA Pytorch container the following were not installed and had to be manually installed: 

pip install braceexpand
pip install webdataset
pip install transformers
pip install pytorch_lightning
pip install rapidfuzz
pip install megatron

**Steps/Code to reproduce bug**

Download NVIDIA Pytorch container
Mount the NeMo directory
run python setup.py install in the NeMo dir
try to run data/import_datasets.py from the examples dir

In addition I am getting the following after installing the above:

 from megatron import mpu
ImportError: cannot import name 'mpu' from 'megatron' (/opt/conda/lib/python3.8/site-packages/megatron/__init__.py)

**Expected behavior**

All required packages should be installed during install

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

 - Docker
 - python setup.py install
 - sudo docker run --gpus all -it --rm -v HOMEDIR/NeMo:/NeMo --shm-size=8g -p 8888:8888 -p 6006:6006 --ulimit memlock=-1 --ulimit stack=67108864 --device=/dev/snd nvcr.io/nvidia/pytorch:21.05-py3

**Environment details**

NA

**Additional context**

NVIDIA GTX 1050ti
