dockerfile added

[ondratra]

Hello,
I wanted to try this repository but I was unwilling to install dependencies on my system globally. That's why I added Dockerfile for the project.

It can be built and run as easily as

docker build -t solstice .
docker run --volume /path/to/my/folder:/myVolumeName -t solstice -i /myVolumeName/path/to/source.sol