Jenkins fixes

Jenkinsfile

@@ -61,13 +61,14 @@ pipeline {
                 FIREFOX_BIN = "firefox/firefox-bin"
             }
             steps {
-                sh 'gulp install'
+                nodejs('node-lts') {
                     sh 'karma start'
                     sh 'gulp docker'
                     sh 'gulp backendUnitTest --junit'
                     sh 'docker rm -f salix-db'
                 }
             }
+        }
         stage('Docker') {
             environment {
                 CREDS = credentials('docker-registry')