lispy.el (lispy-move-down): improve

* lispy.el (lispy-move-down): This should now work.

(foo |(bar) baz)

->

(foo baz |(bar))
lispy.el (lispy-move-up): improve

* lispy.el (lispy-move-up): Will move sexp even if previous element
  isn't a sexp.

* lispy-test.el (lispy-move-up): Add test.
  (lispy-move-down): Add test.
lispy.el: simplify "w"/"s"

* lispy.el (lispy-move-up): Simplify.
  (lispy-move-down): Simplify.

Fixes #26