add docker image for onedns

Dockerfile

@@ -0,0 +1,18 @@
+FROM python:2.7.12-slim
+MAINTAINER Harvard Unviersity Faculty of Arts and Sciences Research Computing
+
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+COPY . /usr/src/app
+RUN pip install --no-cache-dir -r /usr/src/app/requirements.txt
+RUN pip install --no-cache-dir /usr/src/app/
+
+RUN apt-get clean
+RUN rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+EXPOSE 53
+
+ENTRYPOINT ["/usr/local/bin/onedns"]
+
+CMD ["daemon"]