Make the build a bit faster

Have the ADD ./app be a bit later on in the dockerfile, so that we don't
have to reinstall stuff whenever the code changes.

Dockerfile

@@ -13,16 +13,16 @@ RUN echo "daemon off;" >> /etc/nginx/nginx.conf
 #fix for long server names
 RUN sed -i 's/# server_names_hash_bucket/server_names_hash_bucket/g' /etc/nginx/nginx.conf
 
-RUN mkdir /app
-WORKDIR /app
-ADD . /app
-
 RUN wget -P /usr/local/bin https://godist.herokuapp.com/projects/ddollar/forego/releases/current/linux-amd64/forego
 RUN chmod u+x /usr/local/bin/forego
 
 RUN wget https://github.com/jwilder/docker-gen/releases/download/0.3.2/docker-gen-linux-amd64-0.3.2.tar.gz
 RUN tar xvzf docker-gen-linux-amd64-0.3.2.tar.gz
 
+RUN mkdir /app
+WORKDIR /app
+ADD . /app
+
 EXPOSE 80
 ENV DOCKER_HOST unix:///tmp/docker.sock