Newer virtualenv also for Azure pipelines

Author: frenzymadness

.azure-pipelines/steps/run-tests-windows.yml

@@ -24,7 +24,7 @@ steps:
     Set-Acl "R:\Temp" $acl
   displayName: Set RAMDisk Permissions
 
-- bash: pip install --upgrade 'virtualenv<20' setuptools tox
+- bash: pip install --upgrade 'virtualenv' setuptools tox
   displayName: Install Tox
 
 - script: tox -e py -- -m unit -n auto --junit-xml=junit/unit-test.xml

.azure-pipelines/steps/run-tests.yml

@@ -4,7 +4,7 @@ steps:
   inputs:
     versionSpec: '$(python.version)'
 
-- bash: pip install --upgrade 'virtualenv<20' setuptools tox
+- bash: pip install --upgrade 'virtualenv' setuptools tox
   displayName: Install Tox
 
 - script: tox -e py -- -m unit -n auto --junit-xml=junit/unit-test.xml