CI: add a jenkinsfile

Jenkinsfile

@@ -0,0 +1,30 @@
+pipeline {
+    agent any
+    options {
+        buildDiscarder(logRotator(numToKeepStr: '5'))
+    }
+    stages {
+        stage('Build') {
+            agent {
+                label 'linux'
+            }
+            steps {
+                echo 'Building..'
+                script {
+                    sh '''
+                    #!/bin/bash
+
+                    chmod +x gradlew
+                    ./gradlew clean build
+                    '''
+                }
+            }
+
+            post {
+                always {
+                    archiveArtifacts artifacts: 'build/libs/*.jar'
+                }
+            }
+        }
+    }
+}