0.4.0

CHANGES:

• Do not report errors about dropped or uninterpreted attributes
  starting with _ (#46, fix #40, @diml)

• Fix he special_function rule for dotted operators and allow
  Longident.parse to parse dotted operators (#44, @Octachron)

• Port to dune and remove use of bash (#45, @rgrinberg)

• Ignore all attribites starting with _ (#46, @diml)

• Reserve the reason and refmt namespaces (#46, @diml)

• Reserve the metaocaml namespace (#50, @rgrinberg)

• Fix attribute extraction for Otag/Rtag (#51, @xclerc)

• Do not relocate files unless -loc-filename is passed (#55, @hhugo)

• Perserve the filename in the output (#56, @hhugo)