Update testing environment, attempt to use new formula format

Add ubuntu map.jinja

* Update docs
* Add auxiliar scripts
* Add missing headers

* Use the correct keyring for the OS (a refactor of the changes suggested in #41)

* Use latest pre-salted images
* Move from serverspec to inspec
* Fix failing tests

updated repositories entries for sane naming across Debian and Ubuntu entries
updated repo entries for security as syntax differs between Debian and Ubuntu
added repo entries for -updates (previously known as volatile)
updated map to use explicitly use grain os instead of implicitly use os_family
removed distribution_updates variable - syntax was Debian specific and invailid for Ubuntu
tested against Debian/stretch and Ubuntu/xenial

syncing fork to original

also pass check when opt_data is a number

Syncing fork to the original repository

added -y flag to apt-get calls

apt.conf.d

remove_* was recently changed to always place empty file, but just set
perms if not present, without replace.

Do the same with that option.

- Add template file
- Add pillar example

fix warning on preferences as not managed

[WARNING ] State for file: /etc/apt/preferences - Neither 'source' nor
'contents' nor 'contents_pillar' nor 'contents_grains' was defined, yet
'replace' was set to 'True'. As there is no source to replace the file
with, 'replace' has been set to 'False' to avoid reading the file
unnecessarily.

Now, if file.managed, but when content is not changed (no source,
contents, ...), avoid the warning.

fix iteritems python3

Move keyring package name configuration to pillar

#32 replace httpredir by deb.debian.org

add opts to repo name

contributed initialy by @javierbertoli <javier@netmanagers.com.ar>

fixes #30

Fixes #30

Permit an absent preferences pillar data key

adding support for Origins-Pattern in unattended upgrade

Minor fixes

Deleting the file causes "could not open file '/etc/apt/sources.list'"
warnings. Better to keep it around but just remove its contents.

fix pillar lookup and whitespacing