Add Dockerfile for ecommerce build

docker/build/ecommerce/Dockerfile

+FROM edxops/precise-common:latest
+MAINTAINER edxops
+
+RUN apt-get update
+
+ADD . /edx/app/edx_ansible/edx_ansible
+COPY docker/build/ecommerce/ansible_overrides.yml /
+WORKDIR /edx/app/edx_ansible/edx_ansible/docker/plays
+
+COPY docker/build/ecommerce/ansible_overrides.yml /
+RUN /edx/app/edx_ansible/venvs/edx_ansible/bin/ansible-playbook ecommerce.yml -i '127.0.0.1,' -c local -t "install:base,install:system-requirements,install:configuration,install:app-requirements,install:code" -e@/ansible_overrides.yml
+COPY docker/build/xqueue/docker-run.sh /
+ENTRYPOINT ["/docker-run.sh"]
+EXPOSE 8130