Test json fix

Author: alextwoods

gems/aws-partitions/lib/aws-partitions.rb

@@ -212,7 +212,8 @@ def default_partition_list
       def defaults
         @defaults ||= begin
           path = File.expand_path('../../partitions.json', __FILE__)
-          JSON.load(File.read(path))
+          defaults = JSON.parse(File.read(path), freeze: true)
+          defaults.merge('partitions' => defaults['partitions'].dup)
         end
       end