Don't error out if xml is requested with something else than repo

lib/travis/api/app/responders/xml.rb

@@ -15,6 +15,10 @@ module Travis::Api::App::Responders
       started: 'Building'
     }
 
+    def apply?
+      super && resource.is_a?(Repository)
+    end
+
     def apply
       halt TEMPLATE % data
     end

spec/integration/v2/repositories_spec.rb

@@ -86,6 +86,11 @@ describe 'Repos' do
     response.should deliver_cc_xml_for(Repository.by_slug('svenfuchs/minimal').first)
   end
 
+  it 'does not respond with cc.xml for /repos list' do
+    response = get '/repos', {}, 'HTTP_ACCEPT' => 'application/xml; version=2'
+    response.status.should == 406
+  end
+
   describe 'GET /repos/svenfuchs/minimal.png?branch=foo,bar' do
     let(:on_foo) { Factory(:commit, branch: 'foo') }
     let(:on_bar) { Factory(:commit, branch: 'bar') }