fix integration

1 job for master in 22 seconds (queued for 1 second)
Name Stage Failure
failed
build Build
$ make
ocaml setup.ml -configure
ocamlfind: Package `lwt_ppx' not found
W: Field 'pkg_lwt_ppx' is not set: Command ''/home/opam/.opam/4.05/bin/ocamlfind' query -format %d lwt_ppx > '/tmp/oasis-6b4f4d.txt'' terminated with error code 2
E: Cannot find findlib package lwt_ppx
E: Failure("1 configuration error")
make: *** [setup.data] Error 1
Makefile:34: recipe for target 'setup.data' failed
ERROR: Job failed: exit code 1