Removing specs usage from the CookieMapSpec.

As per the discussion over on this [twitter/util](https://github.com/twitter/util/pull/97) PR I was going to help out with moving a bunch of twitter projects over to cross compile with 2.11. This is just a "sample" PR to make sure the style and everything was going to be okay to be merged. 
Do we want the triple equals for asserts?
```scala
assert(cookie.value === "value")
```
It gives a more informative error message.  Also, the more you have, the better your equality tests will be.*

*That's science.  Or javascript.