Fixed packages requirements and version issues.

[kartikeyporwal]

1. moviepy==0.2.3.5 caused

    Traceback (most recent call last):
    File "inference.py", line 3, in <module>
        import moviepy.editor as mov_editor
    File "/home/kartikey/anaconda3/envs/celeb_env/lib/python3.6/site-packages/moviepy/editor.py", line 26, in <module>
        imageio.plugins.ffmpeg.download()
    File "/home/kartikey/anaconda3/envs/celeb_env/lib/python3.6/site-packages/imageio/plugins/ffmpeg.py", line 38, in download
        "imageio.ffmpeg.download() has been deprecated. "
    RuntimeError: imageio.ffmpeg.download() has been deprecated. Use 'pip install imageio-ffmpeg' instead.

which could be fixed by upgrading to moviepy==1.0.0.

2. Another error - ImportError: cannot import name 'Optional'
   could be solved by not installing pretrainedmodels==0.7.4 as it was installing torchvision==0.6.0 which caused the problem but torchvision==0.2.1 worked.

[dvoitekh]

@kartikeyporwal thank you. we haven't updated dependencies for a while and thus some of the warnings became errors