Adds option to unpause pipeline.

[trobert2]

Thank you for contributing to the Concourse Pipeline Resource!

• Have you made this pull request to the develop branch?
• Have you run the tests locally?

[trobert2]

Implements #28

[vito]

Minor nit: unpaused: true or unpause: true? Any preference? The latter "feels" more natural to me.

[trobert2]

@vito, thanks for replying. The pipeline's state is going to be unpaused so this one sounds better to me. I can do whatever you prefer if you strongly disagree

[vito]

I guess I'm thinking of other resources which use the verb form when it's an explicit action to be taken, e.g. the git resource has rebase: true and merge: true (https://github.com/concourse/git-resource#out-push-to-a-repository). I would prefer that for consistency but I don't want to force the issue. :) I'm fine with it either way.

[vito]

I can see the other argument, though, which is that a user shouldn't know whether it's an explicit action to be taken or whether it's a modifier passed straight to Concourse, e.g. fly set-pipeline --unpaused flag or something. So I'm OK with either. :+1:

[trobert2]

given this second statement and that concourse tends to be declarative, this is a concourse resource it puts in the end, wouldn't unpaused make more sense?

[vito]

Yeah, sounds good. Merging, thanks!