bpmn won't progress to next task

diagram.bpmn

<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" id="Definitions_1" targetNamespace="http://bpmn.io/schema/bpmn">
  <bpmn:process id="Process_1" isExecutable="true">
    <bpmn:startEvent id="StartEvent_0u6igzm" name="Start">
      <bpmn:outgoing>SequenceFlow_0dj0shd</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:task id="Task_1j1u5jd" name="Send email">
      <bpmn:incoming>SequenceFlow_0dj0shd</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_1yqx4t9</bpmn:outgoing>
    </bpmn:task>
    <bpmn:task id="Task_0fqh9ez" name="Create user">
      <bpmn:incoming>SequenceFlow_1yqx4t9</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_0c2y283</bpmn:outgoing>
    </bpmn:task>
    <bpmn:endEvent id="EndEvent_0lggshx" name="End">
      <bpmn:incoming>SequenceFlow_0c2y283</bpmn:incoming>
    </bpmn:endEvent>
    <bpmn:sequenceFlow id="SequenceFlow_0dj0shd" sourceRef="StartEvent_0u6igzm" targetRef="Task_1j1u5jd" />
    <bpmn:sequenceFlow id="SequenceFlow_1yqx4t9" sourceRef="Task_1j1u5jd" targetRef="Task_0fqh9ez" />
    <bpmn:sequenceFlow id="SequenceFlow_0c2y283" sourceRef="Task_0fqh9ez" targetRef="EndEvent_0lggshx" />
  </bpmn:process>
  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_1">
      <bpmndi:BPMNShape id="StartEvent_0u6igzm_di" bpmnElement="StartEvent_0u6igzm">
        <dc:Bounds x="27.204950495049502" y="43.07326732673266" width="36" height="36" />
        <bpmndi:BPMNLabel>
          <dc:Bounds x="0.20495049504950202" y="79.07326732673266" width="90" height="20" />
        </bpmndi:BPMNLabel>
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Task_1j1u5jd_di" bpmnElement="Task_1j1u5jd">
        <dc:Bounds x="115.2049504950495" y="21" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Task_0fqh9ez_di" bpmnElement="Task_0fqh9ez">
        <dc:Bounds x="276.2049504950495" y="21" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="EndEvent_0lggshx_di" bpmnElement="EndEvent_0lggshx">
        <dc:Bounds x="432.2049504950495" y="43" width="36" height="36" />
        <bpmndi:BPMNLabel>
          <dc:Bounds x="405.2049504950495" y="79" width="90" height="20" />
        </bpmndi:BPMNLabel>
      </bpmndi:BPMNShape>
      <bpmndi:BPMNEdge id="SequenceFlow_0dj0shd_di" bpmnElement="SequenceFlow_0dj0shd">
        <di:waypoint xsi:type="dc:Point" x="63" y="61" />
        <di:waypoint xsi:type="dc:Point" x="115" y="61" />
        <bpmndi:BPMNLabel>
          <dc:Bounds x="44" y="36" width="90" height="20" />
        </bpmndi:BPMNLabel>
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="SequenceFlow_1yqx4t9_di" bpmnElement="SequenceFlow_1yqx4t9">
        <di:waypoint xsi:type="dc:Point" x="215" y="61" />
        <di:waypoint xsi:type="dc:Point" x="276" y="61" />
        <bpmndi:BPMNLabel>
          <dc:Bounds x="200.5" y="36" width="90" height="20" />
        </bpmndi:BPMNLabel>
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="SequenceFlow_0c2y283_di" bpmnElement="SequenceFlow_0c2y283">
        <di:waypoint xsi:type="dc:Point" x="376" y="61" />
        <di:waypoint xsi:type="dc:Point" x="432" y="61" />
        <bpmndi:BPMNLabel>
          <dc:Bounds x="359" y="36" width="90" height="20" />
        </bpmndi:BPMNLabel>
      </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>
</bpmn:definitions>

diagram.js

exports.Start = function (data, done) {
    console.log("Started business process");
    done();
};

exports.Send_email = function (data, done) {
    console.log("Sending email");
    done(data);
};

exports.Create_user = function (data, done) {
    console.log("Creating user");
    setTimeout(function() {
        console.log("Created user");
        done(data);
    }, 2000);
};

exports.End = function (data, done) {
    console.log("Ending business process");
    done();
};

/**
 * @param {String} eventType Possible types are: "activityFinishedEvent", "callHandler"
 * @param {String?} currentFlowObjectName The current activity or event
 * @param {String} handlerName
 * @param {String} reason Possible reasons:
 *                          - no handler given
 *                          - process is not in a state to handle the incoming event
 *                          - the event is not defined in the process
 *                          - the current state cannot be left because there are no outgoing flows
 */
exports.defaultEventHandler = function(eventType, currentFlowObjectName, handlerName, reason, done) {
    // Called, if no handler could be invoked.
    console.log("-- Handled by default handler --")
    console.log("* Flow object:   \t" + currentFlowObjectName);
    console.log("* Handler name:  \t" + handlerName);
    console.log("* Reason:        \t" + reason);
    console.log("--");
    
    done();
};

exports.defaultErrorHandler = function(error, done) {
    // Called if errors are thrown in the event handlers
    console.error(error);
    done();
};

exports.onBeginHandler = function(currentFlowObjectName, data, done) {
    // do something
    console.log("Begin: " + currentFlowObjectName);
    done(data);
};

exports.onEndHandler = function(currentFlowObjectName, data, done) {
    // do something
    console.log("End: " + currentFlowObjectName);
    done(data);
};

index.js

var bpmn = require("bpmn");
var logLevels = require('bpmn').logLevels;

console.log("Starting");

bpmn.createUnmanagedProcess(__dirname + "/diagram.bpmn", function(err, myProcess) {
    myProcess.setLogLevel(logLevels.debug);
    myProcess.triggerEvent("Start");
});

console.log("Finished");