Skip a test on JRuby

The test_accept_verbatim_nl_after_backslash is failed on JRuby
because Ripper on JRuby fails to lexical analyse around escaped newline.
I filed a issue for it: jruby/jruby#4787
The "skip" should be removed after the issue is resolved.

Author: aycabta

test/test_rdoc_markup_to_html.rb

@@ -452,6 +452,9 @@ def test_accept_verbatim_parseable_error
   end
 
   def test_accept_verbatim_nl_after_backslash
+    # TODO: Remove "skip" after the issue is resolved: https://github.com/jruby/jruby/issues/4787
+    # This "skip" is for strange behavior around escaped newline on JRuby
+    skip if defined? JRUBY_VERSION
     verb = @RM::Verbatim.new("a = 1 if first_flag_var and \\\n", "  this_is_flag_var\n")
 
     @to.start_accepting