Added dockerfile

[rokett]

Hoping you'll consider adding this small change to include a dockerfile.

Not necessary by any means, as people can create their own and pull the config, but it's nice to include one within the repo.

Cheers!

[terickson]

So we are fine with including a Dockerfile with the project but instead of cloning a specific version of the code, if its going to be included with the source code, we feel it should use the source code its cloned with to build the container from the current code base. That way its not a shock to the user that the container does not use the current code in the project. Is there a reason you want this to be version specific? If so maybe there is another way we can accommodate that.

[rokett]

The thinking there was just that the version number could change with each new release, so that the dockerfile in the repo always builds a current release.

That makes sense if you want to provide a container image as part of a release, but maybe doesn't for people who just pull the repo. I'd say whatever makes most sense to you as the maintainers would be ok...it's equally not hard for anyone wanting to use guac to create their own dockerfile, so maybe this just provides an example for them.

[rokett]

For my purposes I have created myself a dockerfile for future use which I have stored at https://github.com/rokett/Dockerfiles.

I forked this project primarily to add the TLS and config flag for setting the guacd address, so I'm inclined to remove my fork now.

I just wanted to check you didn't still want to review this PR before I do that. I'll likely remove the the fork next week at some point.

Thanks for accepting the other changes.