Fix time zone handling for cookie expiry time

PhantomJS parses the HTTP date format in the local time zone, even if it
is actually GMT. So we send the milliseconds from epoch instead to get
around that.

Closes #228

README.md

@@ -309,6 +309,8 @@ Include as much information as possible. For example:
     [Issue #203] (@arnvald)
 *   Fix the `:js_errors` option. Previously errors were not being
     reported, but would still cause commands to fail. [Issue #229]
+*   Fix incorrect time zone handling when setting cookie expiry time
+    [Issue #228]
 
 ### 1.0.2 ###
 

lib/capybara/poltergeist/browser.rb

@@ -153,8 +153,8 @@ module Capybara::Poltergeist
     end
 
     def set_cookie(cookie)
-      if cookie[:expires].respond_to?(:httpdate)
-        cookie[:expires] = cookie[:expires].httpdate
+      if cookie[:expires]
+        cookie[:expires] = cookie[:expires].to_i * 1000
       end
 
       command 'set_cookie', cookie

lib/capybara/poltergeist/cookie.rb

@@ -29,7 +29,7 @@ module Capybara::Poltergeist
     end
 
     def expires
-      Time.parse @attributes['expires'] if @attributes['expires']
+      Time.at @attributes['expiry'] if @attributes['expiry']
     end
   end
 end