Returns true if provided IAM credentials are ready to use.

def CirrusIamUserReady(iam_aws_id, iam_aws_secret):
  """ Returns true if provided IAM credentials are ready to use. """
  is_ready = False
  try:
    s3 = core.CreateTestedS3Connection(iam_aws_id, iam_aws_secret)
    if s3:
      if core.CirrusAccessIdMetadata(s3, iam_aws_id).IsInitialized():
        is_ready = True            
  except boto.exception.BotoServerError as e:
    print e 
    
  return is_ready