'Parses request headers and extracts part od the X-Amz-Target
that corresponds to a method of DynamoHandler
ie: X-Amz-Target: DynamoDB_20111205.ListTables -> ListTables'

def get_endpoint_name(self, headers):

    match = (headers.get(u'x-amz-target') or headers.get(u'X-Amz-Target'))
    if match:
        return match.split(u'.')[1]
