Treat uneval nodes as comments

[tobias]

Uneval nodes throw an UnsupportedOperationException if node/sexpr is
called on them, which will break get-first-sexp if it is given
file-content that starts with #_ whatever.

This includes uneval nodes in the set of nodes we should skip when
looking for first & last sexps.

Before submitting a PR make sure the following things have been done (and denote this
by checking the relevant checkboxes):

• The commits are consistent with our contribution guidelines
  • there is no CONTRIBUTING.md, I assume this should be .github/CONTRIBUTING.md?
• You've added tests (if possible) to cover your change(s)
• All tests are passing (run lein do clean, test)
  • No! I get:

Exception in thread "main" java.lang.RuntimeException: Map literal must contain an even number of forms, compiling:(refactor_nrepl/artifacts.clj:25:1)

But I get the same thing on master, so I'm not sure what is going on there.

• Code inlining with mranderson works and tests pass with inlined code (run ./build.sh install -- takes a long time)
  • There is no ./build.sh. I have installed this with lein with-profile +plugin.mranderson/config install and have confirmed it is working for me.
• You've updated the changelog (if adding/changing user-visible functionality)
• You've updated the readme (if adding/changing user-visible functionality)

Thanks!

[bbatsov]

But I get the same thing on master, so I'm not sure what is going on there.

Well, it I see on the CI tests mostly pass (apart from the known issue with Clojure 1.8). Thanks for fixing this!