refactor; use new minitest api

Author: abargnesi

.build/test/test-examples.rb

@@ -4,7 +4,7 @@
 require 'minitest/autorun'
 require 'minitest/unit'
 
-class ExamplesTest < MiniTest::Unit::TestCase
+class ExamplesTest < Minitest::Test
 
   def setup
     root = Pathname(File.dirname(File.expand_path __FILE__)) + '..' + '..'

.build/test/test-schema.rb

@@ -3,7 +3,7 @@
 require "minitest/autorun"
 require "minitest/unit"
 
-class SchemaTest < MiniTest::Unit::TestCase
+class SchemaTest < Minitest::Test
 
   def test_validate_schema
     root = Pathname(File.dirname(File.expand_path __FILE__)) + '..' + '..'