python version is needed for spec test

manifests/pyvenv.pp

@@ -37,7 +37,7 @@
 
   if $ensure == 'present' {
     $python_version = $version ? {
-        'system' => $::python3_version,
+        'system' => $facts['python3_version'],
         default  => $version,
     }
 
@@ -56,7 +56,7 @@
     }
 
     # pyvenv is deprecated since 3.6 and will be removed in 3.8
-    if (versioncmp($::python3_version, '3.6') >=0) {
+    if (versioncmp($facts['python3_version'], '3.6') >=0) {
       $virtualenv_cmd = "${python::exec_prefix}python${python_version}  -m venv"
     } else {
       $virtualenv_cmd = "${python::exec_prefix}pyvenv-${python_version}"

spec/default_module_facts.yml

@@ -0,0 +1,3 @@
+---
+python_version: "2.7"
+python3_version: ~

spec/defines/pyvenv_spec.rb

@@ -4,15 +4,18 @@
   on_supported_os.each do |os, facts|
     context("on #{os} ") do
       let :facts do
-        facts
+        # python3 is required to use pyvenv
+        facts.merge({
+          :python3_version => '3.4',
+        })
       end
       let :title do
         '/opt/env'
       end
 
       it {
         is_expected.to contain_file('/opt/env')
-        is_expected.to contain_exec('python_virtualenv_/opt/env').with_command('pyvenv --clear  /opt/env')
+        is_expected.to contain_exec('python_virtualenv_/opt/env').with_command('pyvenv-3.4 --clear  /opt/env')
       }
 
       describe 'when ensure' do
@@ -28,6 +31,6 @@
           }
         end
       end
-    end
+    end #context
   end
 end