Fix #131 - Syntax error

plug.vim

@@ -694,7 +694,7 @@ function! s:update_impl(pull, force, args) abort
     try
       call mkdir(g:plug_home, 'p')
     catch
-      return s:err(printf('Invalid plug directory: %s.'
+      return s:err(printf('Invalid plug directory: %s. '.
               \ 'Try to call plug#begin with a valid directory', g:plug_home))
     endtry
   endif

test/workflow.vader

@@ -1138,6 +1138,17 @@ Execute (#130 Proper cleanup of on-demand loading triggers):
   Assert !exists(':EmojiCommandExtra'), 'EmojiCommandExtra defined'
   Assert empty(mapcheck('<Plug>(EmojiMappingExtra)')), '<Plug>(EmojiMappingExtra) defined'
 
+**********************************************************************
+Execute (#131 Syntax error):
+  call plug#begin('/no-permission')
+  Plug 'junegunn/vim-emoji'
+  call plug#end()
+
+  redir => out
+  silent PlugInstall
+  redir END
+  Assert out =~ 'Invalid plug directory: /no-permission'
+
 Execute (Cleanup):
   silent! call system('rm -rf '.temp_plugged)
   silent! call system('rm -rf '.temp_plugged)