ci: two python versions

Jenkinsfile

@@ -1,13 +1,14 @@
 pipeline {
   agent none
   stages {
-    stage('Tests') {
+    stage('CPU') {
+      parallel {
+        stage('3.9'){
           agent {
             docker {
               image 'python:3.9'
               args '--user 0:0'
             }
-
           }
           steps {
             sh 'pip install pip --upgrade --progress-bar off'
@@ -15,6 +16,20 @@ pipeline {
             sh './tests/test_examples.sh examples'
           }
         }
-
+        stage('3.8'){
+          agent {
+            docker {
+              image 'python:3.8'
+              args '--user 0:0'
+            }
+          }
+          steps {
+            sh 'pip install pip --upgrade --progress-bar off'
+            sh 'pip install .[all] --progress-bar off'
+            sh './tests/test_examples.sh examples'
+          }
+        }
+      }
+    }
   }
 }