Ensure that Jbuilder.encode properly forwards arguments to .new

The initializer previously accepted an options hash, but now takes
kwargs. So the encode method also needs to accept (and forward)
kwargs.

Author: flavorjones

lib/jbuilder.rb

@@ -28,8 +28,8 @@ def initialize(
   end
 
   # Yields a builder and automatically turns the result into a JSON string
-  def self.encode(*args, &block)
-    new(*args, &block).target!
+  def self.encode(...)
+    new(...).target!
   end
 
   BLANK = Blank.new

test/jbuilder_test.rb

@@ -936,4 +936,11 @@ class JbuilderTest < ActiveSupport::TestCase
     result = JSON.load(Jbuilder.encode { |json| json.time Time.parse("2018-05-13 11:51:00.485 -0400") })
     assert_equal "2018-05-13T11:51:00.485-04:00", result["time"]
   end
+
+  test "encode forwards options to new" do
+    Jbuilder.encode(key_formatter: 1, ignore_nil: 2) do |json|
+      assert_equal 1, json.instance_eval{ @key_formatter }
+      assert_equal 2, json.instance_eval{ @ignore_nil }
+    end
+  end
 end