Add currency to PayPal SDK URL

[seand7565]

Adds a currency to the PayPal SDK URL, which is necessary when the
currency is not USD. Otherwise, PayPal will throw an error and checkout
will be aborted.

Also makes our order creation process respect the current pricing
options.

closes #107

[bobomimi]

Hi
Thank you very much for the quick response and action but it still not working for me and I'm getting the same error when I changing the default currency in spree.rb .

best regards

terminal:
CACHE Spree::State Load (0.0ms) SELECT "spree_states".* FROM "spree_states" WHERE "spree_states"."id" = $1 LIMIT $2 [["id", 3441], ["LIMIT", 1]]
CACHE Spree::Country Load (0.0ms) SELECT "spree_countries".* FROM "spree_countries" WHERE "spree_countries"."id" = $1 LIMIT $2 [["id", 233], ["LIMIT", 1]]
Completed 201 Created in 1580ms (Views: 0.8ms | ActiveRecord: 4.6ms | Allocations: 30342)

[seand7565]

@bobomimi Are you using the the latest version of solidus_paypal_commerce_platform sourced from Github? I haven't released a minor version yet, so the rubygems version of this extension is still out of date.

[bobomimi]

my bad, working perfectly fine when the source is Github.
thank you so much