Improve test of mruby-numeric-ext GEM

mrbgems/mruby-numeric-ext/test/numeric.rb

@@ -2,8 +2,8 @@
 # Numeric(Ext) Test
 
 assert('Integer#chr') do
-  assert_equal(65.chr, "A")
-  assert_equal(0x42.chr, "B")
+  assert_equal("A", 65.chr)
+  assert_equal("B", 0x42.chr)
 
   # multibyte encoding (not support yet)
   assert_raise(RangeError) { 12345.chr }