Use "Environment" instead of "Rscons::Environment" in build tests

build_tests/json_to_yaml/Rsconscript

@@ -1,5 +1,5 @@
 build do
-  Rscons::Environment.new do |env|
+  Environment.new do |env|
     require 'json'
     require 'yaml'
     env.add_builder(:JsonToYaml) do |target, sources, cache, env, vars|