Complete TLS/SSL Support, near-mirror of Docker CLI

[momer]

This is an expansion of @denibertovic 's work on #187

I'd re-done some of his work today, and expanded on it quite a bit by the time I realized it existed here. I've forked his commit to give him credit, and expanded on his work.

Note: This is my first time writing Python longer than 5-10 lines. Let me know if there are any code smells! I know the Exception class can be a sticking point, but I felt it was important to remind the user where the TLS API comes from, and to DRY that up a bit.

Also, I left a bunch of comments to help readers understand why some of the additions are necessary. Tests pass, and I connect fine using the options; but, alas, I haven't written any new tests for this PR.

[momer]

Thoughts?

[shin-]

Thanks!

Ok, so you'll want to rebase this first, especially because we already have an exceptions errors module in master which you'll want to merge with your own.

Otherwise this looks good. Maybe extract all the additional checks and configs from __init__() and into a separate method so it doesn't become too crowded?

[momer]

Sounds good - will get to this tonight/later this week

[shin-]

@momer Are you still working on this?

[momer]

@shin- sorry for the delay had a hectic deadline to meet. Changes in docker-py have since made my updates break tests in master. Would love it if you could pick up here and patch forward to current version. I may have time in the next month to get to this, but it's low on my priority unfortunately.

[shin-]

No worries, thanks for the quick reply.

[shin-]

I'm closing this since we're continuing the discussion on #250 :)