Add option to send extra options to Braintree

We'll be able to use this to send along the device data for fraud
prevention. (As well as slowly build it out to support other Braintree
options.)

app/models/solidus_paypal_braintree/gateway.rb

@@ -15,6 +15,13 @@ class Gateway < ::Spree::PaymentMethod
       store_in_vault_on_success: true
     }.freeze
 
+    ALLOWED_BRAINTREE_OPTIONS = [
+      :device_data,
+      :device_session_id,
+      :merchant_account_id,
+      :order_id
+    ]
+
     # This is useful in feature tests to avoid rate limited requests from
     # Braintree
     preference(:client_sdk_enabled, :boolean, default: true)
@@ -32,12 +39,14 @@ def payment_source_class
     # @api public
     # @param money_cents [Number, String] amount to authorize
     # @param source [Source] payment source
+    # @params gateway_options [Hash]
+    #   extra options to send along. e.g.: device data for fraud prevention
     # @return [Response]
-    def purchase(money_cents, source, _gateway_options)
+    def purchase(money_cents, source, gateway_options)
       result = ::Braintree::Transaction.sale(
         amount: dollars(money_cents),
-        payment_method_nonce: source.nonce,
-        options: PAYPAL_OPTIONS
+        options: PAYPAL_OPTIONS,
+        **transaction_options(source, gateway_options)
       )
 
       Response.build(result)
@@ -48,12 +57,14 @@ def purchase(money_cents, source, _gateway_options)
     # @api public
     # @param money_cents [Number, String] amount to authorize
     # @param source [Source] payment source
+    # @params gateway_options [Hash]
+    #   extra options to send along. e.g.: device data for fraud prevention
     # @return [Response]
-    def authorize(money_cents, source, _gateway_options)
+    def authorize(money_cents, source, gateway_options)
       result = ::Braintree::Transaction.sale(
         amount: dollars(money_cents),
-        payment_method_nonce: source.nonce,
-        options: PAYPAL_AUTHORIZE_OPTIONS
+        options: PAYPAL_AUTHORIZE_OPTIONS,
+        **transaction_options(source, gateway_options)
       )
 
       Response.build(result)
@@ -134,5 +145,15 @@ def payment_profiles_supported?
     def dollars(cents)
       Money.new(cents).dollars
     end
+
+    def transaction_options(source, options)
+      params = options.select do |key, _|
+        ALLOWED_BRAINTREE_OPTIONS.include?(key)
+      end
+
+      params[:payment_method_nonce] = source.nonce
+
+      params
+    end
   end
 end