Value for 'Expires' header needs to be a string

liquor-cabinet.rb

@@ -46,7 +46,7 @@ class LiquorCabinet < Sinatra::Base
               'Access-Control-Expose-Headers' => 'ETag'
       headers['Access-Control-Allow-Origin'] = env["HTTP_ORIGIN"] if env["HTTP_ORIGIN"]
       headers['Cache-Control'] = 'no-cache'
-      headers['Expires'] = 0
+      headers['Expires'] = '0'
 
       @user, @key = params[:user], params[:key]
       @directory = params[:splat] && params[:splat].first || ""

spec/directories_spec.rb

@@ -71,7 +71,7 @@ describe "Directories" do
       get "/jimmy/tasks/"
 
       last_response.status.must_equal 200
-      last_response.headers["Expires"].must_equal 0
+      last_response.headers["Expires"].must_equal "0"
     end
 
     context "when If-None-Match header is set" do

spec/riak_spec.rb

@@ -40,7 +40,7 @@ describe "App with Riak backend" do
 
     it "has caching headers set" do
       last_response.status.must_equal 200
-      last_response.headers["Expires"].must_equal 0
+      last_response.headers["Expires"].must_equal "0"
     end
   end