use newer ocaml for Coq master

d49bb07b · Ralf Jung · 7177cd8d · d49bb07b
Commit d49bb07b authored Sep 30, 2018 by Ralf Jung
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -29,6 +29,7 @@ variables:
 build-coq.dev:
  <<: *template
  variables:
+    OCAML: "ocaml-base-compiler.4.07.0"
    OPAM_PINS: "coq version dev"
    VALIDATE: "1"