Add rufo fixer for ruby files

autoload/ale/fixers/rufo.vim

@@ -0,0 +1,20 @@
+" Author: Fohte (Hayato Kawai) https://github.com/fohte
+" Description: Integration of Rufo with ALE.
+
+call ale#Set('ruby_rufo_executable', 'rufo')
+
+function! ale#fixers#rufo#GetCommand(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'ruby_rufo_executable')
+    let l:exec_args = l:executable =~? 'bundle$'
+    \   ? ' exec rufo'
+    \   : ''
+
+    return ale#Escape(l:executable) . l:exec_args . ' %t'
+endfunction
+
+function! ale#fixers#rufo#Fix(buffer) abort
+    return {
+    \   'command': ale#fixers#rufo#GetCommand(a:buffer),
+    \   'read_temporary_file': 1,
+    \}
+endfunction