docker-py should support same URL schemes as Docker

[bfirsh]

Fig received docker/compose#88 because it blindly passes DOCKER_HOST to the base_url arg to Client.

Maybe base_url should support things like tcp://, as per https://github.com/dotcloud/docker/blob/2723133a69a292abaa021afff98de127bda57b4e/utils/utils.go#L753-L807 . Alternatively, it could be a separate constructor method.

[shin-]

Already in master: see #140

[bfirsh]

Sorry, I should have been clearer. docker-py supports some of the values of DOCKER_HOST. Here are some things it doesn't support, for example:

• tcp://
• :4243
• localhost
• localhost:4243

It should all work if the logic from Docker's ParseHost is reproduced.

[shin-]

I'll hold out on making changes for now because I believe ParseHost will undergo some changes very soon in the main project, which could invalidate or change the scope of this request. Leaving it open until then.