Merlin reports wrong error for “shadowed” identifiers

[smondet]

With Merlin pinned to https://github.com/the-lambda-church/merlin.git#reason-0.0

I get the same error with Reason and OCaml files (and from Atom and Neovim):

In a file:

let x = 42;
let x () => 42;

I get this error from Merlin:

Error: Values do not match:
         let x : unit => int
       is not included in
         let x : int: /Users/sebastienmondet/test2.re:1

[let-def]

Fixed in master. Need to find a way to sync with Reason.