Removed syntastic and replaced it with ale

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

sources_non_forked/ale/ale_linters/json/jsonlint.vim

@@ -0,0 +1,27 @@
+" Author: KabbAmine <amine.kabb@gmail.com>
+
+function! ale_linters#json#jsonlint#Handle(buffer, lines) abort
+    " Matches patterns like the following:
+    " line 2, col 15, found: 'STRING' - expected: 'EOF', '}', ',', ']'.
+
+    let l:pattern = '^line \(\d\+\), col \(\d*\), \(.\+\)$'
+    let l:output = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        call add(l:output, {
+        \   'lnum': l:match[1] + 0,
+        \   'col': l:match[2] + 0,
+        \   'text': l:match[3],
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+call ale#linter#Define('json', {
+\   'name': 'jsonlint',
+\   'executable': 'jsonlint',
+\   'output_stream': 'stderr',
+\   'command': 'jsonlint --compact -',
+\   'callback': 'ale_linters#json#jsonlint#Handle',
+\})