[ruby/reline] Change a test method name to more appropriate

https://github.com/ruby/reline/commit/d014cc85b7

test/reline/yamatanooroti/test_rendering.rb

@@ -1197,7 +1197,7 @@ begin
       EOC
     end
 
-    def test_bottom
+    def test_scroll_at_bottom_for_dialog
       start_terminal(10, 40, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl --autocomplete}, startup_message: 'Multiline REPL.')
       write("\n\n\n\n\n\n")
       write("def hoge\n\n\n\n\n\n\nend\C-p\C-p\C-p\C-e")