Description of problem:

Test results:
>> Issue: [B303:blacklist] Use of insecure MD2, MD4, MD5, or SHA1 hash function.
   Severity: Medium   Confidence: High
   Location: octavia/common/tls_utils/cert_parser.py:364
   More Info: https://bandit.readthedocs.io/en/latest/blacklists/blacklist_calls.html#b303-md5
363	    return data_models.TLSContainer(
364	        id=hashlib.sha1(cert.get_certificate()).hexdigest(),
365	        primary_cn=get_primary_cn(cert),

--------------------------------------------------
>> Issue: [B303:blacklist] Use of insecure MD2, MD4, MD5, or SHA1 hash function.
   Severity: Medium   Confidence: High
   Location: octavia/common/utils.py:41
   More Info: https://bandit.readthedocs.io/en/latest/blacklists/blacklist_calls.html#b303-md5
40	def base64_sha1_string(string_to_hash):
41	    hash_str = hashlib.sha1(string_to_hash.encode('utf-8')).digest()
42	    b64_str = base64.b64encode(hash_str, str.encode('_-', 'ascii'))

Version-Release number of selected component (if applicable): Latest 10


How reproducible: 100%


Steps to Reproduce:
1. Clone repo
2. Checkout 13 branch and run 'tox -e pep8'