<!-- Love localstack? Please consider supporting our collective:
👉  https://opencollective.com/localstack/donate -->

Under utils/common.py, 

TIMESTAMP_FORMAT_MILLIS = '%Y-%m-%dT%H:%M:%S.%fZ'

The %f produces time with microseconds, for example: 2020-03-18T19:43:18.115783Z.


However, when interacting the AWS s3 and sns apis, I receive DateTimes like this:

2020-03-02T22:32:13.240Z
i.e. milliseconds. 

This seems like a simple change to the utils. TIMESTAMP_FORMAT_MILLIS is named as if it should be millis as well. This is seems like a simple change. Is there a reason it should be microseconds?
return all([os.path.exists(f) for f in files])
    if target_file and not overwrite and os.path.exists(target_file):
        key_file_name = '%s.key' % target_file
        cert_file_name = '%s.crt' % target_file
        try:
            
            content = load_file(target_file)
            key_start = '-----BEGIN PRIVATE KEY-----'
            key_end = '-----END PRIVATE KEY-----'
            cert_start = '-----BEGIN CERTIFICATE-----'
            cert_end = '-----END CERTIFICATE-----'
            key_content = content[content.index(key_start): content.index(key_end) + len(key_end)]
            cert_content = content[content.index(cert_start): content.index(cert_end) + len(cert_end)]
            save_file(key_file_name, key_content)
            save_file(cert_file_name, cert_content)
        except Exception as e:
            LOG.info('Unable to store key/cert files for custom SSL certificate: %s' % e)
        if all_exist(key_file_name, cert_file_name):
            return target_file, cert_file_name, key_file_name
    if random and target_file:
        if '.' in target_file:
            target_file = target_file.replace('.', '.%s.' % short_uid(), 1)
        else:
            target_file = '%s.%s' % (target_file, short_uid())
    
    k = crypto.PKey()
    k.generate_key(crypto.TYPE_RSA, 2048)