add support for running with Docker

[nivkner]

was having trouble with the installation process using pip directly (python 3.6.7 seems to be incompatible with tensorflow 1.15.2),
so i created a dockerfile based on https://github.com/deniszh/DeepCreamPy, which is out of date.

[pink-red]

I tried it, it works!

[pink-red]

Also, for mosaic decensoring, the command should be changed slightly:

docker run --rm -v $(pwd)/models:/opt/DeepCreamPy/models -v $(pwd)/decensor_input:/opt/DeepCreamPy/decensor_input -v $(pwd)/decensor_input_original:/opt/DeepCreamPy/decensor_input_original -v $(pwd)/decensor_output:/opt/DeepCreamPy/decensor_output deepcreampy --is_mosaic=true

Specifically, it requires adding these options:

• -v $(pwd)/decensor_input_original:/opt/DeepCreamPy/decensor_input_original
• --is_mosaic=true