replace some comments by echo of command, so blocks are not empty

Jenkinsfile

@@ -6,7 +6,7 @@ pipeline {
     stages {
         stage('Unit Tests') {
             steps {
-                // sh 'tox -rv'
+                echo "sh 'tox -rv'"
             }
             post {
                 always {
@@ -16,7 +16,7 @@ pipeline {
                         // utils.publish_coverage_native('index.html')
                         // utils.publish_pylint('pylint.out')
                     }
-                    // junit '*_results.xml'
+                    echo "junit '*_results.xml'"
                 }
             }
         }