reenable cookies in request so login will work again

Cookies are now off by default in the current version of the request module:
https://github.com/mikeal/request/pull/587

As a result, login no longer works. This reenables it.
create a new cookie jar for each api instance
Merge pull request #21 from Survos/request-cookies

reenable cookies in request so login will work again
v0.3.7