installing nemo_toolkit[all]==1.0.0b3 installs torch=1.8.0
Please start using rc1 version, we are going to release it soon
```
 python -m pip install git+https://github.com/NVIDIA/NeMo.git@r1.0.0rc1#egg=nemo_toolkit[all]
```
**Describe the bug**

I created a fresh conda environment and installed PyTorch==1.7.1 and nemo_toolkit[all]==1.0.0b3.
Although it says that NeMo is not supporting PyTorch 1.8, installing NeMo uninstalled PyTorch 1.7.1 and installed 1.8 version. I am guessing this is a bug. I even got the following message:

```
ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
torchaudio 0.7.2 requires torch==1.7.1, but you have torch 1.8.0 which is incompatible.
```

**Steps/Code to reproduce bug**

- Create a new conda environment with Python 3.8.2
- Install PyTorch 1.7.1 with pip
- Install NeMo 1.0.0b3 with pip

**Expected behavior**

Should install PyTorch 1.7.1 instead of 1.8

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

 - Environment location: Windows 10 
 - Method of NeMo install: pip install nemo_toolkit[all]==1.0.0b3

**Environment details**

If NVIDIA docker image is used you don't need to specify these.
Otherwise, please provide:
- OS version: Windows 10
- PyTorch version: 1.7.1 - 1.8
- Python version: 3.8.2
