Docker sass

Docekrfile

# TODO: pin versions
FROM alpine
MAINTAINER Tomasz Wesolowski "tomek@wesolowski.it"

RUN set -ex \
    && apk add --update --no-cache ruby \
    && apk add --update --no-cache --virtual build-dependencies \
        build-base \
        ruby-dev \
        libffi-dev \
    && gem install --no-document \
        json \
        compass \
    && apk del build-dependencies

ENTRYPOINT ["sass"]