Lib 'cvxpy' is missing at 'insightface/reconstruction/PBIDR/requirements.txt' to be installed

The file [`insightface/reconstruction/PBIDR/code/evaluation/eval.py`](https://github.com/deepinsight/insightface/blob/master/reconstruction/PBIDR/code/evaluation/eval.py) imports the `'cvxpy'` library, but it isn't listed at the file [`insightface/reconstruction/PBIDR/requirements.txt`](https://github.com/deepinsight/insightface/blob/master/reconstruction/PBIDR/requirements.txt) to be installed.

Maybe the [`insightface/reconstruction/PBIDR/requirements.txt`](https://github.com/deepinsight/insightface/blob/master/reconstruction/PBIDR/requirements.txt) should be like that:

```
----------------------------------
vtk
numpy
opencv-python
scikit-image
scipy
Pillow
argparse
GPUtil
pyhocon
plotly
cvxpy
----------------------------------
```

In addition, the command `'pip install requirements.txt'` at the file [insightface/blob/master/reconstruction/PBIDR/INSTALL.md](https://github.com/deepinsight/insightface/blob/master/reconstruction/PBIDR/INSTALL.md#install-other-requirments) requires a `'-r'` parameter to install all libs, like that:

```
----------------------------------
pip install -r requirements.txt
----------------------------------
```

I hope it helps!