fix typo in html attributes

When I ran rake, I got an error (below), but my only change was to fix a typo.

purple-unicorn:~/Dropbox/railsbridge/railsbridge_website naomi$ rake
/Users/naomi/.rvm/rubies/ruby-1.9.3-p125/bin/ruby -S rspec spec/app_spec.rb spec/contents_spec.rb spec/markdown_spec.rb spec/media_wiki_spec.rb spec/site_index_spec.rb spec/site_spec.rb spec/site_syntax_spec.rb spec/step_page_spec.rb spec/step_spec.rb spec/titleizer_spec.rb --format d --backtrace --color
/Users/naomi/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:55:in `require': cannot load such file -- wrong/adapters/rspec (LoadError)
	from /Users/naomi/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:55:in `require'
	from /Users/naomi/Dropbox/railsbridge/railsbridge_website/spec/spec_helper.rb:6:in `<top (required)>'
	from /Users/naomi/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
	from /Users/naomi/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
	from /Users/naomi/Dropbox/railsbridge/railsbridge_website/spec/app_spec.rb:1:in `<top (required)>'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/configuration.rb:896:in `load'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/configuration.rb:896:in `block in load_spec_files'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/configuration.rb:896:in `each'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/configuration.rb:896:in `load_spec_files'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/command_line.rb:22:in `run'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/runner.rb:80:in `run'
	from /Users/naomi/.rvm/gems/ruby-1.9.3-p125/gems/rspec-core-2.14.4/lib/rspec/core/runner.rb:17:in `block in autorun'
/Users/naomi/.rvm/rubies/ruby-1.9.3-p125/bin/ruby -S rspec spec/app_spec.rb spec/contents_spec.rb spec/markdown_spec.rb spec/media_wiki_spec.rb spec/site_index_spec.rb spec/site_spec.rb spec/site_syntax_spec.rb spec/step_page_spec.rb spec/step_spec.rb spec/titleizer_spec.rb --format d --backtrace --color failed