remove unused travis ci file
remove unused travis ci file

inhabitedtype/ocaml-cohttp,mor1/ocaml-cohttp,mor1/ocaml-cohttp,edwintorok/ocaml-cohttp,inhabitedtype/ocaml-cohttp,inhabitedtype/ocaml-cohttp,edwintorok/ocaml-cohttp,edwintorok/ocaml-cohttp,mor1/ocaml-cohttp