Add Jenkinsfile.

Jenkinsfile

@@ -0,0 +1,18 @@
+pipeline {
+  agent { docker { image 'python:3.9' } }
+  stages {
+    stage('build') {
+      steps {
+        sh 'pip install pipenv'
+	sh 'pipenv shell --python 3.9'
+	sh 'pipenv install'
+      }
+    }
+    stage('test') {
+      steps {
+        sh './run_tests.sh'
+      }   
+    }
+  }
+}
+JENKINSFILE