title: Terraform ELB S3 Permissions Issue
body: <p>I am having an issue using Terraform (v0.9.2) adding services to an ELB (I'm using: <a href="https://github.com/segmentio/stack/blob/master/s3-logs/main.tf" rel="noreferrer">https://github.com/segmentio/stack/blob/master/s3-logs/main.tf</a>).</p>
  
  <p>When I run <code>terraform apply</code> I get this error:</p>
  
  <pre><code>* module.solr.module.elb.aws_elb.main: 1 error(s) occurred:
  
  * aws_elb.main: Failure configuring ELB attributes: 
      InvalidConfigurationRequest: Access Denied for bucket: my-service-
      logs. Please check S3bucket permission
      status code: 409, request id: xxxxxxxxxx-xxxx-xxxx-xxxxxxxxx
  </code></pre>
  
  <p>My service looks like this:</p>
  
  <pre><code>module "solr" {
    source = "github.com/segmentio/stack/service"
    name = "${var.prefix}-${terraform.env}-solr"
    environment = "${terraform.env}"
    image = "123456789876.dkr.ecr.eu-west-2.amazonaws.com/my-docker-image"
    subnet_ids = "${element(split(",", module.vpc_subnets.private_subnets_id), 3)}"
    security_groups = "${module.security.apache_solr_group}"
    port = "8983"
    cluster = "${module.ecs-cluster.name}"
    log_bucket = "${module.s3_logs.id}"
  
    iam_role = "${aws_iam_instance_profile.ecs.id}"
    dns_name = ""
    zone_id = "${var.route53_zone_id}"
  }
  </code></pre>
  
  <p>My s3-logs bucket looks like this:</p>
  
  <pre><code>module "s3_logs" {
    source = "github.com/segmentio/stack/s3-logs"
    name = "${var.prefix}"
    environment = "${terraform.env}"
    account_id = "123456789876"
  }
  </code></pre>
  
  <p>I checked in S3 and the bucket policy looks like this:</p>
  
  <pre><code>{
    "Version": "2012-10-17",
    "Id": "log-bucket-policy",
    "Statement": [
    {
    "Sid": "log-bucket-policy",
    "Effect": "Allow",
    "Principal": {
    "AWS": "arn:aws:iam::123456789876:root"
    },
    "Action": "s3:PutObject",
    "Resource": "arn:aws:s3:::my-service-logs/*"
    }
    ]
  }
  </code></pre>
  
  <p>As far as I can see ELB should have access to the S3 bucket to store the logs (it's running in the same AWS account).</p>
  
  <p>The bucket and the ELB are all in <code>eu-west-2</code>.</p>
  
  <p>Any ideas on what the problem could be would be much appreciated.</p>