Removed syntastic and replaced it with ale

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

sources_non_forked/ale/ale_linters/css/csslint.vim

@@ -0,0 +1,18 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: This file adds support for checking CSS code with csslint.
+
+function! ale_linters#css#csslint#GetCommand(buffer) abort
+    let l:csslintrc = ale#path#FindNearestFile(a:buffer, '.csslintrc')
+    let l:config_option = !empty(l:csslintrc)
+    \   ? '--config=' . ale#Escape(l:csslintrc)
+    \   : ''
+
+    return 'csslint --format=compact ' . l:config_option . ' %t'
+endfunction
+
+call ale#linter#Define('css', {
+\   'name': 'csslint',
+\   'executable': 'csslint',
+\   'command_callback': 'ale_linters#css#csslint#GetCommand',
+\   'callback': 'ale#handlers#css#HandleCSSLintFormat',
+\})