lispy.el (lispy--mark): new function

* lispy.el (lispy-mark-symbol): Simplify.
  (lispy-mode-map): Rearrange bindings.
lispy-test.el (lispy-mark): new test
lispy-test.el (lispy-with): print the mark if it's active

* lispy-test.el (lispy-forward): Update.
  (lispy-move-up): Update.
  (lispy-move-down): Update.
  (lispy-mark): Update.
lispy.el (lispy-move-up): improve
lispy.el (lispy-move-down): improve