Removed syntastic and replaced it with ale

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

sources_non_forked/ale/ale_linters/ruby/brakeman.vim

@@ -0,0 +1,47 @@
+" Author: Eddie Lebow https://github.com/elebow
+" Description: Brakeman, a static analyzer for Rails security
+
+let g:ale_ruby_brakeman_options =
+\   get(g:, 'ale_ruby_brakeman_options', '')
+
+function! ale_linters#ruby#brakeman#Handle(buffer, lines) abort
+    let l:output = []
+    let l:json = ale#util#FuzzyJSONDecode(a:lines, {})
+    let l:sep = has('win32') ? '\' : '/'
+    " Brakeman always outputs paths relative to the Rails app root
+    let l:rails_root = ale#ruby#FindRailsRoot(a:buffer)
+
+    for l:warning in get(l:json, 'warnings', [])
+        let l:text = l:warning.warning_type . ' ' . l:warning.message . ' (' . l:warning.confidence . ')'
+        let l:line = l:warning.line != v:null ? l:warning.line : 1
+
+        call add(l:output, {
+        \   'filename': l:rails_root . l:sep .  l:warning.file,
+        \   'lnum': l:line,
+        \   'type': 'W',
+        \   'text': l:text,
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+function! ale_linters#ruby#brakeman#GetCommand(buffer) abort
+    let l:rails_root = ale#ruby#FindRailsRoot(a:buffer)
+
+    if l:rails_root is? ''
+        return ''
+    endif
+
+    return 'brakeman -f json -q '
+    \    . ale#Var(a:buffer, 'ruby_brakeman_options')
+    \    . ' -p ' . ale#Escape(l:rails_root)
+endfunction
+
+call ale#linter#Define('ruby', {
+\    'name': 'brakeman',
+\    'executable': 'brakeman',
+\    'command_callback': 'ale_linters#ruby#brakeman#GetCommand',
+\    'callback': 'ale_linters#ruby#brakeman#Handle',
+\    'lint_file': 1,
+\})