Removed syntastic and replaced it with ale

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

sources_non_forked/ale/autoload/ale/fixers/gofmt.vim

@@ -0,0 +1,18 @@
+" Author: aliou <code@aliou.me>
+" Description: Integration of gofmt with ALE.
+
+call ale#Set('go_gofmt_executable', 'gofmt')
+call ale#Set('go_gofmt_options', '')
+
+function! ale#fixers#gofmt#Fix(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'go_gofmt_executable')
+    let l:options = ale#Var(a:buffer, 'go_gofmt_options')
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \       . ' -l -w'
+    \       . (empty(l:options) ? '' : ' ' . l:options)
+    \       . ' %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction