Updated .gitignore.
Updated .gitignore.

samoht/ocaml-vchan,djs55/ocaml-vchan,mirage/ocaml-vchan,mirage/ocaml-vchan,samoht/ocaml-vchan,djs55/ocaml-vchan,djs55/ocaml-vchan,mirage/ocaml-vchan,samoht/ocaml-vchan