title: AWS CloudFormation custom resources not working
body: <p>I have created a custom resource to trigger an AWS Lambda function and get an instance id as output. The custom resource is not creating in CloudFormation.</p>
  
  <pre><code>     Code: 
          ZipFile: !Sub |
            import json
            import boto3  
            import os
  
            def lambda_handler(event, context):
              ec2 = boto3.client('ec2', 'us-east-1')
              response = ec2.describe_instances()
              for reservation_data in response['Reservations']:
                for instance_data in reservation_data['Instances']:
                    for tags_data in instance_data['Tags']:
                      print(instance_data['InstanceId'])
  
        Runtime: python3.7
        Timeout: 200
  
    MyFrontEndTest: 
      Type: Custom::lambdatrigger
      Properties: 
        ServiceToken: !GetAtt lambdaFunction3.Arn
        ActionType: MyFrontEndTest
  Outputs:
    Message:
      Description: Gets the instance id 
      Value: !GetAtt 'MyFrontEndTest'
  </code></pre>