Use 3.4's ssl.create_default_context when available
Fix usage of CERT_NONE with an SSLContext

Don't update the SSLContext.protocol version since the value is only
important in SSLContext.__new__ and it will not have the desired effect
Try using check_hostname = False if CERT_NONE
Add create_urllib3_context and use it internally
First working stub context
Call out platform-specific branches

Remove now duplicated code
Fix up test coverage
Last bit of test coverage and hopefully a fix for some tests
Use correct set of ciphers
Address further feedback
Pass ciphers on any version which actually allows for them
Update ssl_wrap_socket to accept ciphers
Update exception message

[ci skip]
Replace and update ssl_wrap_socket's docstring
Reduce scope of exception handling in ssl_wrap_socket

Only catch and handle IOErrors and OSErrors as the comment intended
Remove poorly designed test
Merge pull request #473 from sigmavirus24/use-create_default_context

Use 3.4's ssl.create_default_context when available
CHANGES for #473
Nag about SecurityWarning every time.
CHANGES for #496