Removed syntastic and replaced it with ale

Read more here:
https://github.com/w0rp/ale

sources_non_forked/ale/ale_linters/ocaml/merlin.vim

@@ -0,0 +1,17 @@
+" Author: Andrey Popp -- @andreypopp
+" Description: Report errors in OCaml code with Merlin
+
+if !exists('g:merlin')
+    finish
+endif
+
+function! ale_linters#ocaml#merlin#Handle(buffer, lines) abort
+    return merlin#ErrorLocList()
+endfunction
+
+call ale#linter#Define('ocaml', {
+\   'name': 'merlin',
+\   'executable': 'ocamlmerlin',
+\   'command': 'true',
+\   'callback': 'ale_linters#ocaml#merlin#Handle',
+\})

sources_non_forked/ale/ale_linters/ocaml/ols.vim

@@ -0,0 +1,14 @@
+" Author: Michael Jungo <michaeljungo92@gmail.com>
+" Description: A language server for OCaml
+
+call ale#Set('ocaml_ols_executable', 'ocaml-language-server')
+call ale#Set('ocaml_ols_use_global', 0)
+
+call ale#linter#Define('ocaml', {
+\   'name': 'ols',
+\   'lsp': 'stdio',
+\   'executable_callback': 'ale#handlers#ols#GetExecutable',
+\   'command_callback': 'ale#handlers#ols#GetCommand',
+\   'language_callback': 'ale#handlers#ols#GetLanguage',
+\   'project_root_callback': 'ale#handlers#ols#GetProjectRoot',
+\})