[DRE-maint] Bug#676977: ruby-redcarpet: FTBFS: test suite can't find nokogiri

[Aaron M. Ucko]

Source: ruby-redcarpet
Version: 2.1.1-1
Severity: serious
Justification: fails to build from source

Builds of ruby-redcarpet in minimal environments, such as the
autobuilders, have been failing due to an undeclared build dependency on
ruby-nokogiri:

  ./test/redcarpet_test.rb:12:in `require': no such file to load -- nokogiri (LoadError)
  	from ./test/redcarpet_test.rb:12
  	from -e:1:in `require'
  	from -e:1
  	from -e:1:in `each'
  	from -e:1
  ERROR: Test "ruby1.8" failed. Exiting.
  dh_auto_install: dh_ruby --install /.../ruby-redcarpet-2.1.1/debian/ruby-redcarpet returned exit code 1
  make: *** [binary-arch] Error 1

Please add ruby-nokogiri to ruby-redcarpet's Build-Depends (and
Depends if appropriate), and check with pbuilder or the like that
nothing else is missing.

Thanks!