Creates an object out of the httplib2.Response, which is just a subclass of dict. Since we want to make the response a little easier to deal with, this class will objectify it.
Returns True if:
- the cookie name appears in the response
- if value is not None, the values are equal
- if any of the attributes match
For example, to check to see if the HttpOnly and path attribute are set:
assertCookie("cookie_name", attrs={'HttpOnly': True, "Path": "/"})
Returns True if name was in the headers and, if value is True, whether or not the values match, or False otherwise.