Add Debian 11 and 12 support

Change name of Debian package ifenslave-2.6 to ifenslave.

As of Debian 11, the package ifenslave-2.6 is no longer available,
causing puppet run failure when using bonds.

Debian 9 and 10 support is maintained because they also have the
ifenslave package (with ifenslave-2.6 marked as transitional).

This drops support for bonds in Debian 8, which is EOL since June 2018.

README.md

@@ -134,6 +134,11 @@ This class also provides fine-grained control over which packages to install and
 how to install them. The documentation for the parameters exposed can be found
 [here](https://github.com/voxpupuli/puppet-network/blob/master/manifests/init.pp).
 
+Bonding on Debian requires the package [ifenslave](https://packages.debian.org/search?suite=all&section=all&arch=any&searchon=names&keywords=ifenslave),
+which is installed automatically when a bond is defined. This package was
+renamed in Debian 9, and therefore bonding does not work on Debian
+versions prior to 9.
+
 Note: you may also need to update your master's plugins (run on your puppet master):
 
     puppet agent -t --noop

manifests/bond/setup.pp

@@ -2,7 +2,7 @@
 class network::bond::setup {
   case $facts['os']['family'] {
     'Debian': {
-      package { 'ifenslave-2.6':
+      package { 'ifenslave':
         ensure => present,
       }
     }

metadata.json

@@ -27,7 +27,9 @@
     {
       "operatingsystem": "Debian",
       "operatingsystemrelease": [
-        "8"
+        "10",
+        "11",
+        "12"
       ]
     },
     {

spec/classes/bond/setup_spec.rb

@@ -8,6 +8,6 @@
       }
     end
 
-    it { is_expected.to contain_package('ifenslave-2.6') }
+    it { is_expected.to contain_package('ifenslave') }
   end
 end