refactor http_post headers params

lib/weixin_authorize.rb

@@ -17,7 +17,7 @@ module WeixinAuthorize
     def http_post_without_token(url, payload={}, headers={}, endpoint="plain")
       post_api_url = endpoint_url(endpoint, url)
       payload = MultiJson.dump(payload) if endpoint == "plain" # to json if invoke "plain"
-      load_json(RestClient.post(post_api_url, payload, headers))
+      load_json(RestClient.post(post_api_url, payload, :params => headers))
     end
 
     # return hash

lib/weixin_authorize/client.rb

@@ -45,7 +45,7 @@ module WeixinAuthorize
       end
 
       def http_post(url, payload={}, headers={}, endpoint="plain")
-        headers = {:params => access_token_param.merge(headers)}
+        headers = access_token_param.merge(headers)
         WeixinAuthorize.http_post_without_token(url, payload, headers, endpoint)
       end