elasticsearch-cli 0.5 lower bound on yojson
Fails with
```
(cd _build/default && /home/opam/.opam/4.08/bin/ocamlc.opt -w -40 -g -bin-annot -I src/.es.eobjs -I /home/opam/.opam/4.08/lib/atd -I /home/opam/.opam/4.08/lib/atdgen -I /home/opam/.opam/4.08/lib/base -I /home/opam/.opam/4.08/lib/base/caml -I /home/opam/.opam/4.08/lib/base/md5 -I /home/opam/.opam/4.08/lib/base/shadow_stdlib -I /home/opam/.opam/4.08/lib/base_bigstring -I /home/opam/.opam/4.08/lib/base_quickcheck -I /home/opam/.opam/4.08/lib/bin_prot -I /home/opam/.opam/4.08/lib/bin_prot/shape -I /home/opam/.opam/4.08/lib/biniou -I /home/opam/.opam/4.08/lib/bytes -I /home/opam/.opam/4.08/lib/core_kernel -I /home/opam/.opam/4.08/lib/core_kernel/base_for_tests -I /home/opam/.opam/4.08/lib/core_kernel/rope -I /home/opam/.opam/4.08/lib/curl -I /home/opam/.opam/4.08/lib/devkit -I /home/opam/.opam/4.08/lib/devkit/core -I /home/opam/.opam/4.08/lib/easy-format -I /home/opam/.opam/4.08/lib/extlib -I /home/opam/.opam/4.08/lib/extunix -I /home/opam/.opam/4.08/lib/fieldslib -I /home/opam/.opam/4.08/lib/jane-street-headers -I /home/opam/.opam/4.08/lib/libevent -I /home/opam/.opam/4.08/lib/lwt -I /home/opam/.opam/4.08/lib/lwt/unix -I /home/opam/.opam/4.08/lib/mmap -I /home/opam/.opam/4.08/lib/netstring -I /home/opam/.opam/4.08/lib/netsys -I /home/opam/.opam/4.08/lib/oUnit -I /home/opam/.opam/4.08/lib/ocaml/threads -I /home/opam/.opam/4.08/lib/parsexp -I /home/opam/.opam/4.08/lib/pcre -I /home/opam/.opam/4.08/lib/ppx_assert/runtime-lib -I /home/opam/.opam/4.08/lib/ppx_bench/runtime-lib -I /home/opam/.opam/4.08/lib/ppx_compare/runtime-lib -I /home/opam/.opam/4.08/lib/ppx_enumerate/runtime-lib -I /home/opam/.opam/4.08/lib/ppx_expect/collector -I /home/opam/.opam/4.08/lib/ppx_expect/common -I /home/opam/.opam/4.08/lib/ppx_expect/config -I /home/opam/.opam/4.08/lib/ppx_hash/runtime-lib -I /home/opam/.opam/4.08/lib/ppx_inline_test/config -I /home/opam/.opam/4.08/lib/ppx_inline_test/runtime-lib -I /home/opam/.opam/4.08/lib/ppx_module_timer/runtime -I /home/opam/.opam/4.08/lib/ppx_sexp_conv/runtime-lib -I /home/opam/.opam/4.08/lib/re2 -I /home/opam/.opam/4.08/lib/re2/c -I /home/opam/.opam/4.08/lib/result -I /home/opam/.opam/4.08/lib/seq -I /home/opam/.opam/4.08/lib/sexplib -I /home/opam/.opam/4.08/lib/sexplib0 -I /home/opam/.opam/4.08/lib/splittable_random -I /home/opam/.opam/4.08/lib/stdio -I /home/opam/.opam/4.08/lib/time_now -I /home/opam/.opam/4.08/lib/typerep -I /home/opam/.opam/4.08/lib/variantslib -I /home/opam/.opam/4.08/lib/yojson -I /home/opam/.opam/4.08/lib/zip -no-alias-deps -o src/.es.eobjs/elastic_t.cmi -c -intf src/elastic_t.pp.mli)
File "src/elastic_t.mli", line 4, characters 12-25:
4 | type json = Yojson.Safe.t
^^^^^^^^^^^^^
Error: Unbound type constructor Yojson.Safe.t
```
Signed-off-by: Marcello Seri <marcello.seri@gmail.com>