Jenkins config nodejs

- added nodejs plugin and config

Jenkinsfile

@@ -5,15 +5,19 @@ pipeline {
         stage('Stylecheck') {
         steps {
             echo 'Checking Style...'
-            sh 'npm i'
-            sh 'npm i tslint --dev'
-            sh 'tslint src/**/*.ts'
+            nodejs {
+                sh 'npm i'
+                sh 'npm i tslint --dev'
+                sh 'tslint src/**/*.ts'
+            }
         }
         }
         stage('Build') {
             steps {
                 echo 'Building...'
-                sh 'ng build --prod'
+                nodejs {
+                    sh 'ng build --prod'
+                }
             }
         }
     }