DO-51 Jenkins CI (#48)

* DO-51 Jenkins CI
* DO-51 refactor

Jenkinsfile

@@ -0,0 +1,24 @@
+#!groovy
+
+pipeline {
+    agent {
+        docker { image 'maven:3.5.3-jdk-10-slim' }
+    }
+
+    stages {
+        stage('Test') {
+            environment {
+                CODECOV_TOKEN = '5b1293bb-5536-4f60-bfa3-93b4d15eefeb'
+            }
+            steps {
+                sh 'mvn test'
+            }
+            post {
+                always {
+                    junit(testResults: '**/target/surefire-reports/*.xml', allowEmptyResults: true)
+                    sh 'curl -s https://codecov.io/bash | bash'
+                }
+            }
+        }
+    }
+}