title: boto3 list all accounts in an organization
body: <p>I have a requirement that I want to list all the accounts and then write all the credentials in my <code>~/.aws/credentials</code> file. Fir this I am using <code>boto3</code> in the following way</p>
  
  <pre><code>import boto3
  
  client = boto3.client('organizations')
  response = client.list_accounts(
      NextToken='string',
      MaxResults=123
  )
  print(response)
  </code></pre>
  
  <p>This fails with the following error </p>
  
  <pre><code>botocore.exceptions.ClientError: An error occurred (ExpiredTokenException) when calling the ListAccounts operation: The security token included in the request is expired
  </code></pre>
  
  <p>The question is , which token is it looking at? And if I want information about all accounts what credentials should I be using in the <code>credentials</code> file or the <code>config</code> file?</p>