Fix email notification

evaluation.Jenkinsfile

@@ -19,7 +19,7 @@ pipeline {
             	copyArtifacts filter: '*', projectName:'s444421-evaluation/training_and_evaluation', optional: true
             	sh 'ipython ./evaluation.py'
             	archiveArtifacts artifacts: 'build_accuracy.txt, bilds_accuracy.jpg'
-            	sh 'ACC=$(tail -n 1 build_accuracy.txt)'
+            	ACC = sh (script: 'tail -n 1 build_accuracy.txt', returnStdout: true).trim()
             }
         }
     }