Update cookie.rb to handle situations when expires is a DateTime object

[luke-hill]

As mentioned in the commit detailed message

The standard Selenium WebDriver response is to return an object which has an expiry in datetime format.
In order to most effectively work with Selenium, and to provide the smallest barrier possible, co-erce the DateTime object into a Time object and then store it as a HTTP Cookie

The reason for this change is that I have started working with cookies now and need a way of quickly storing them as they have nice uses for other tests and then call them back. I found this library didn't work well with the standard cookies obtained using the W3C conformant endpoints

• See HERE for more info on working with cookies with the Selenium level API
• See HERE for w3c spec for cookies specifically #get_cookie

[flavorjones]

@luke-hill Thank you for opening this pull request!

I added a commit that expands the expires= tests to include a DateTime argument. In general, we like to have tests for any bugfixes or new features to prevent breaking the functionality in the future.

[luke-hill]

Sorry thankyou @flavorjones - I'll be honest as you can tell this was done using inline GH so I wasn't sure if this would be accepted or not. For the other ones I'll fork and make a proper PR for each.

This I imagine would need releasing as/when you do a 1.1

[flavorjones]

This was released yesterday in v1.0.8