Improve Clojure guide

[technomancy]

This should make the Clojure guide a little more idiomatic.

[steveklabnik]

Thanks! Clojure is awesome.

[technomancy]

No problem. Let me know once you get support for Leiningen 2 and I'll be happy to help review docs for that.

[michaelklishin]

@technomancy I disagree with the removal of the Dependency Management section. For a few reasons:

• It is useful for developers to understand what Travis CI Clojure builder runs.
• We usually explain that it is possible to override this, yada yada yada, in or around that section.
• Finally, it is consistent with the rest of the guides.

I take another look and possibly revert that one change.

[michaelklishin]

Also, the :plugins part does not seem to mention that this feature is a 2.0 => 1.7 backport so people who use 1.6.2 locally will have trouble using it. I will add it.

[technomancy]

I see where you're coming from, but I think this is misleading. There is
no reason for the Travis builder to run lein deps. Seeing that it's
done here just reinforces this idea people have that there is some
irrelevant incantation that you have to run before you can start using
Leiningen; basically it's going to cause cargo-culting. I think the
inclusion of the lein protobuf example is a better way to show people
how to override the install process.

I do agree that it's worth mentioning that :plugins will not work in
older versions of Leiningen and that they can use :dev-dependencies in
that case. We should not mention lein plugin install because that
should not be used for plugins that are needed for successful CI runs.

[michaelklishin]

Agreed, documentation examples do form habits and impression of various tools. I will bring Dependency Management section back but only make it say that with Leiningen, it is almost always unnecessary to run lein deps manually.

[michaelklishin]

Also, I will remove lein deps run in the builder when I get to adding Lein 2 support.

[technomancy]

Sounds good; thanks.