Add Dockerfile to repo

[emanuelb]

Add Dockerfile to allow easy building of container that contain enjairfy from git repo, which use COPY . instruction and .dockerignore file if needed.

Currently I use (which do git clone inside the container):

FROM python:3
RUN set -ex; \
    git clone --depth 1 https://github.com/Storyyeller/enjarify/; \
    ln -s /enjarify/enjarify.sh /usr/local/bin/enjarify;
WORKDIR /enjarify/
ENTRYPOINT ["python3", "-O", "-m", "enjarify.main"]
CMD ["--help"]

build:

docker run --rm -t enjarify .

run example:

docker run --rm -ti --network none -v /host/dex-files/:/f/:ro -v /host/jar-from-dex/:/o/:rw --entrypoint /bin/bash enjarify