Remove vim-dispatch

This isn't really needed as Gutentags can update tags async and other
build and linting tools like ALE or coc.nvim will do async.

vim/rc/plugins.rc.vim

@@ -69,7 +69,6 @@ endif
 if (has('nvim') || v:version >= 800)
     call s:smart_source_rc('plugins/neomake')
 else
-    call s:smart_source_rc('plugins/vim-dispatch')
     call s:smart_source_rc('plugins/syntastic')
 endif
 " }}

vim/rc/plugins/vim-dispatch.rc.vim

@@ -1,3 +0,0 @@
-Plug 'tpope/vim-dispatch', { 'on': 'Dispatch' }
-nnoremap <F5> :Make<CR>
-command! TagsUpdate Dispatch ctags -R .

vim/rc/plugins/vim-grepper.rc.vim

@@ -1,7 +1,6 @@
 Plug 'mhinz/vim-grepper'
 " Grepper settings and shortcuts
 let g:grepper = {
-            \ 'dispatch': 1,
             \ 'quickfix': 1,
             \ 'open': 1,
             \ 'switch': 0,