[ADD] docker file and shippable compatibility

Docker odoo image
Building here
[ocaimages/oca-odoo](https://registry.hub.docker.com/u/ocaimages/oca-odoo/builds_history/91750/)
If you look at the [docker documentation](http://docs.docker.com/reference/builder/), the examples use `-y --force-yes`
```dockerfile
FROM debian:stable
RUN apt-get update && apt-get install -y --force-yes apache2
EXPOSE 80 443
VOLUME ["/var/www", "/var/log/apache2", "/etc/apache2"]
ENTRYPOINT ["/usr/sbin/apache2ctl", "-D", "FOREGROUND"]
```
Again, this is about removing unnecessary build steps