Add new “salt.pkgrepo” state

This state enables the official saltstack package repository in order to
always benefit from the latest version. This state currently only works on
Debian and Ubuntu, and aims to implement the installation recommendations
of the official documentation:
http://docs.saltstack.com/en/latest/topics/installation/index.html

README.rst

 Install a minion and configure it in `standalone mode
 <docs.saltstack.com/en/latest/topics/tutorials/standalone_minion.html>`_.
 
+``salt.pkgrepo``
+----------------
+
+Enable the official saltstack package repository in order to always
+benefit from the latest version. This state currently only works on Debian
+and Ubuntu, and aims to implement the `installation recommendations of the
+official documentation
+<http://docs.saltstack.com/en/latest/topics/installation/index.html#platform-specific-installation-instructions>`_.
+
+``salt.pkgrepo.absent``
+-----------------------
+
+Undo the effects of ``salt.pkgrepo``.
+
 ``Configuration``
 =================
 Every option available in the templates can be set in pillar. Settings under 'salt' will be overridden by more specific settings under ``salt['master']``, ``salt['minion']`` or ``salt['cloud']``

salt/pkgrepo/absent.sls

+include:
+  - .{{ grains['os']|lower }}.absent

salt/pkgrepo/debian/absent.sls

+drop-saltstack-pkgrepo:
+  file.absent:
+    - name: /etc/apt/sources.list.d/saltstack.list
+
+drop-saltstack-apt-key:
+  file.absent:
+    - name: /etc/apt/trusted.gpg.d/saltstack.gpg

salt/pkgrepo/debian/init.sls

+saltstack-apt-key:
+  file.managed:
+    - name: /etc/apt/trusted.gpg.d/saltstack.gpg
+    - source: salt://salt/pkgrepo/debian/saltstack.gpg
+    - user: root
+    - group: root
+    - mode: 644
+
+saltstack-pkgrepo:
+  file.managed:
+    - name: /etc/apt/sources.list.d/saltstack.list
+    - source: salt://salt/pkgrepo/debian/sources.list
+    - user: root
+    - group: root
+    - mode: 644
+    - template: jinja
+    - require:
+      - file: saltstack-apt-key
+    # Order: 1 because we can't put a require_in on "pkg: salt-{master,minion}"
+    # because we don't know if they are used.
+    - order: 1

salt/pkgrepo/debian/sources.list

+# saltstack
+deb http://debian.saltstack.com/debian {{ grains['oscodename'] }}-saltstack main

salt/pkgrepo/init.sls

+include:
+  - .{{ grains['os']|lower }}

salt/pkgrepo/ubuntu/absent.sls

+drop-saltstack-pkgrepo:
+  pkgrepo.absent:
+    - ppa: saltstack/salt

salt/pkgrepo/ubuntu/init.sls

+saltstack-pkgrepo:
+  pkgrepo.managed:
+    - ppa: saltstack/salt