Merge pull request #293 from chenrui333/patch-1

chore(ci): update to use ocaml 4.11.1

Author: rn

.circleci/config.yml

@@ -7,7 +7,7 @@ jobs:
       # OPAM seems to be quite unhappy without $TERM and Circle doesn't seem to set one.
       TERM: vt100
       MACOSX_DEPLOYMENT_TARGET: "10.11"
-      OPAM_COMP: 4.10.0
+      OPAM_COMP: 4.11.1
       OPAMVERBOSE: 1
       OPAMYES: 1
       HOMEBREW_NO_AUTO_UPDATE: 1