title: boto3 list all security groups for AWS account
body: <p>Is there any way to list all AWS security groups using boto3 ?</p>
  
  <p>With this code i can get only 5 groups (out of 25 in region)</p>
  
  <pre><code>client = boto3.client('ec2')
  
  response=client.describe_security_groups(
  
  
  
  )
  print response
  </code></pre>
  
  <p>I have 4 VPC's so i tried to get groups for each VPC, added this as filter:</p>
  
  <pre><code>Filters=[
          {
              'Name': 'vpc-id',
              'Values': [
                  'vpc-d60ee9b1',
              ]
          },
      ],
  </code></pre>
  
  <p>But as results i got this:</p>
  
  <pre><code>{u'SecurityGroups': [], 'ResponseMetadata': {'RetryAttempts': 0, 'HTTPStatusCode': 200, 'RequestId': '44f39633-4f21-4c4f-b3f4-82fbce538c5f', 'HTTPHeaders': {'transfer-encoding': 'chunked', 'vary': 'Accept-Encoding', 'server': 'AmazonEC2', 'content-type': 'text/xml;charset=UTF-8', 'date': 'Thu, 03 May 2018 08:25:03 GMT'}}}
  </code></pre>
  
  <p>Tried to filter by region and got:<code>The filter 'region' is invalid</code></p>
  
  <p>However, with AWS CLI it works:</p>
  
  <pre><code>aws ec2 describe-security-groups --region $REGION
  </code></pre>
  
  <p>Does it means i need to stick with AWS CLI or boto3 has syntax  to list ALL security groups for AWS account ?</p>