Summary:
If both the library and binary are named `sledge`, then compilation
works fine and resolves the names correctly, but merlin gets confused
and cannot find the sledge library modules used in the bin sources. So
the binary and library need different names. The name of the library
gets exposed to clients, while the name of the binary only determines
the name of some files in the _build directory, which can be renamed
as desired. Therefore, use the `sledge` name for the library module,
and rename the binary module to `sledge_cli`, but still have dune
install it as `sledge.exe`.
Reviewed By: jvillard
Differential Revision: D20589431
fbshipit-source-id: 14b65907d