Adding SSL/TLS protocol version checks

Bandit can now check for insecure SSL/TLS versions, bad versions
are defined in the config file. By default:
 - SSLv2 is bad
 - SSLv23 is bad
 - SSLv3 is bad
 - TLSv1 is bad

This check works with ssl and pyOpenSSL modules.
A second check will also catch default use of ssl.wrap_socket as
this will use SSLv23 if no option is given. This is an INFO level
check.

Change-Id: I5ff8ea7038eed41b09e4d0ebfcb59bfd7fd4c894
Merge "Adding SSL/TLS protocol version checks"