[O] lisp babel

[Colin Baxter]

Common Lisp in babel steems to have stopped working. With slime running and
(lisp . t) in my emacs init, I now get the error

org-babel-execute:lisp: Cannot open load file: No such file or directory, sly

when I C-cc

#+name: hello-world
#+header: :var message="Hello World!" :exports both
#+begin_src lisp
  (princ message)
#+end_src

In the past, it worked. I thought either slime or sly were needed. 

I'm using org version release_8.3.4-718-g634e12.dirty and GNU Emacs 25.1.50.1.