add in signing option for request_uri. removed uneccessary var for exchange service

Author: melvrickgoh

README.md

@@ -109,5 +109,6 @@ AlipayGlobal::Service::Exchange.current_rates()
 Hash contains objects representing each currency
 
 | Attribute | Data Type | Description |
+| --- | ----------- | ----------- |
 | time | DateTime | When Alipay retrieved the date and time of this currency rate |
 | rate | float | Rate for 1 FOREX Unit : Units of RMB/CNY  |

lib/alipay_global.rb

@@ -8,6 +8,7 @@
 require 'alipay_global/service'
 require 'alipay_global/service/trade'
 require 'alipay_global/service/exchange'
+require 'alipay_global/service/notification'
 
 module AlipayGlobal
 

lib/alipay_global/service.rb

@@ -4,9 +4,10 @@ def self.gateway_url
       AlipayGlobal.environment == "PRODUCTION" ? "https://mapi.alipay.com/gateway.do?" : "https://mapi.alipay.net/gateway.do?"
     end
 
-    def self.request_uri(params)
+    def self.request_uri(params, sign = true)
       uri = URI(gateway_url)
-      uri.query = URI.encode_www_form(sign_params(params))
+      processed_params = sign ? sign_params(params) : params
+      uri.query = URI.encode_www_form(processed_params)
       uri
     end
 

lib/alipay_global/service/exchange.rb

@@ -4,8 +4,6 @@ module AlipayGlobal
   module Service
     module Exchange
 
-      @exchange_format = [:date,:time,:currency,:rate]
-
       def self.current_rates
         exchange_rates_resp = {}
         open(build_request) do |file|