[ADD] Support for Odoo 12.0 and Debian Stretch

[remihb]

Tested with

• buildout

To test with

• standard
• pip

[sebalix]

@remihb
To fix pip install of Odoo 8, change the download URL from https://nightly.odoo.com/8.0/nightly/src/odoo_8.0.latest.zip to https://nightly.odoo.com/8.0/nightly/src/odoo_8.0.20171001.zip.
About buildout builds for Odoo 11 and 12 (Python 3), the branch https://github.com/osiell/anybox.recipe.odoo/archive/feature/python3-fix.tar.gz#egg=anybox.recipe.odoo-1.9.3.dev0 doesn't exist anymore, you can switch on https://github.com/anybox/anybox.recipe.odoo/archive/6b35d0b7d0087b253b7cc8ee5ee3333b846f5c61.tar.gz#egg=anybox.recipe.odoo-1.9.3.dev0 (last commit of master which should include the Python 3 fix).
And for Odoo 12 builds, you miss the Ubuntu-16_Odoo-12.yml file if you want to support it (if not, comment the entries in travis.yml).

If you want to maintain this role in the long run, raise your hand ;)