Create the Dockerfile based on python:3.5.1

This docker file is intentionally built on the Python 3.5.1 official
container to reduce the overall size of a nginx+uwsgi+Flask app
deployment. The installation of nginx is adapted from nginx's official
container, e.g.

https://github.com/nginxinc/docker-nginx/blob/f48d943038eaafd1f69cb14d86db95b3044bd4d8/mainline/jessie/Dockerfile

We also take hints from https://github.com/tiangolo/uwsgi-nginx-docker
on how to install the nginx configuration.

Dockerfile

@@ -0,0 +1,32 @@
+FROM python:3.5.1
+
+MAINTAINER Jonathan Sick <jsick@lsst.org>
+
+# Install nginx.
+# Based on https://github.com/nginxinc/docker-nginx/blob/f48d943038eaafd1f69cb14d86db95b3044bd4d8/mainline/jessie/Dockerfile
+ENV NGINX_VERSION 1.9.12-1~jessie
+
+RUN apt-key adv --keyserver hkp://pgp.mit.edu:80 --recv-keys 573BFD6B3D8FBC641079A6ABABF5BD827BD9BF62 \
+	&& echo "deb http://nginx.org/packages/mainline/debian/ jessie nginx" >> /etc/apt/sources.list \
+	&& apt-get update \
+	&& apt-get install -y \
+		ca-certificates \
+		nginx=${NGINX_VERSION} \
+		gettext-base \
+	&& rm -rf /var/lib/apt/lists/*
+
+# forward request logs to Docker log collector
+RUN ln -sf /dev/stdout /var/log/nginx/access.log \
+	&& ln -sf /dev/stderr /var/log/nginx/error.log
+
+# Remove default configuration from Nginx
+RUN rm /etc/nginx/conf.d/default.conf
+
+# Copy the modified Nginx conf
+COPY nginx.conf /etc/nginx/conf.d/
+
+EXPOSE 80
+
+# Run nginx in foreground to keep the container alive
+# Note that nginx alraedy runs itself as non-root
+CMD ["nginx", "-g", "daemon off;"]