Highlight "given" in specs

https://github.com/jnicklas/capybara#using-capybara-with-rspec

Author: glittershark

autoload/rails.vim

@@ -3879,7 +3879,7 @@ function! rails#buffer_syntax()
           syn keyword rubyRailsTestControllerMethod assert_response assert_redirected_to assert_template assert_recognizes assert_generates assert_routing assert_dom_equal assert_dom_not_equal assert_select assert_select_rjs assert_select_encoded assert_select_email assert_tag assert_no_tag
         endif
       elseif buffer.type_name('spec')
-        syn keyword rubyRailsTestMethod describe context it its specify shared_context shared_examples shared_examples_for shared_context include_examples include_context it_should_behave_like it_behaves_like before after around subject fixtures controller_name helper_name scenario feature background described_class
+        syn keyword rubyRailsTestMethod describe context it its specify shared_context shared_examples shared_examples_for shared_context include_examples include_context it_should_behave_like it_behaves_like before after around subject fixtures controller_name helper_name scenario feature background given described_class
         syn match rubyRailsTestMethod '\<let\>!\='
         syn keyword rubyRailsTestMethod violated pending expect expect_any_instance_of allow allow_any_instance_of double instance_double mock mock_model stub_model xit
         syn match rubyRailsTestMethod '\.\@<!\<stub\>!\@!'