Never use :Runner as default :Rails task

Author: tpope

autoload/rails.vim

@@ -5332,10 +5332,6 @@ function! rails#buffer_setup() abort
     call self.setvar('dispatch', dir . dispatch[0])
   elseif self.name() =~# '^public'
     call self.setvar('dispatch', ':Preview')
-  elseif self.type_name('spec', 'cucumber')
-    call self.setvar('dispatch', ':Runner')
-  elseif self.type_name('test') && !self.app().has_rails5()
-    call self.setvar('dispatch', ':Runner')
   elseif self.name() =~# '^\%(app\|config\|db\|lib\|log\|README\|Rakefile\|test\|spec\|features\)'
     if !exists('dir')
       call self.setvar('dispatch', ':Rails')