Install the right venv package on Debian and RedHat family

REFERENCE.md

@@ -894,6 +894,11 @@ Create a Python3 virtualenv using pyvenv.
 ##### 
 
 ```puppet
+class { 'python':
+  version => 'system',
+  venv    => 'present',
+}
+
 python::pyvenv { '/var/www/project1' :
   ensure       => present,
   version      => 'system',

examples/pyvenv.pp

@@ -1,5 +1,6 @@
 class { 'python':
-  pip     => false,
+  pip     => 'absent',
+  venv    => 'present',
   version => '3',
 }
 

manifests/install.pp

@@ -6,7 +6,11 @@
 #
 class python::install {
   $python = $python::version ? {
-    'system'                 => 'python',
+    'system'                 => $facts['os']['family'] ? {
+      'Debian' => 'python3',
+      'RedHat' => 'python3',
+      default  => 'python',
+    },
     'pypy'                   => 'pypy',
     /\A(python[23]\.[0-9]+)/ => $1,
     /\A(python)?([0-9]+)/    => "python${2}",

manifests/pyvenv.pp

@@ -14,6 +14,11 @@
 # @param python_path Optionally specify python path for creation of virtualenv
 #
 # @example
+#   class { 'python':
+#     version => 'system',
+#     venv    => 'present',
+#   }
+#
 #   python::pyvenv { '/var/www/project1' :
 #     ensure       => present,
 #     version      => 'system',

spec/acceptance/pyvenv_spec.rb

@@ -235,4 +235,21 @@ class { 'python':
       its(:stdout) { is_expected.to match %r{agent.* 0\.1\.2} }
     end
   end
+
+  context "with version => 'system'" do
+    it 'works with no errors' do
+      pp = <<-PUPPET
+      class { 'python':
+        version => 'system',
+        venv    => 'present',
+      }
+      python::pyvenv { '/opt/regress700':
+        ensure => 'present',
+      }
+      PUPPET
+
+      apply_manifest(pp, catch_failures: true)
+      apply_manifest(pp, catch_changes: true)
+    end
+  end
 end

spec/classes/python_spec.rb

@@ -63,6 +63,22 @@
         it { is_expected.to contain_package('python-venv').with(ensure: 'present') } unless facts[:os]['family'] == 'RedHat'
       end
 
+      if facts[:os]['family'] == 'Debian'
+        context "with version => 'system' on Debian family" do
+          let(:params) { { version: 'system', venv: 'present' } }
+
+          it { is_expected.to contain_package('python-venv').with(name: 'python3-venv', ensure: 'present') }
+        end
+      end
+
+      if %w[Debian RedHat].include?(facts[:os]['family'])
+        context "with version => 'system'" do
+          let(:params) { { version: 'system' } }
+
+          it { is_expected.to contain_package('python').with(name: 'python3') }
+        end
+      end
+
       case facts[:os]['family']
       when 'Debian'