ocaml-ctypes is marked for autoremoval from testing

[Debian testing autoremoval watch]

ocaml-ctypes 0.7.0-1 is marked for autoremoval from testing on 2018-01-30

It (build-)depends on packages with these RC bugs:
877548: lwt: lwt FTBFS: Error: This variant or record definition does not match 
that of type Unix.open_flag