Drop test dependency from `mruby-hash-ext` to `mruby-enumerator`

mrbgems/mruby-hash-ext/mrbgem.rake

@@ -4,5 +4,4 @@ MRuby::Gem::Specification.new('mruby-hash-ext') do |spec|
   spec.summary = 'Hash class extension'
   spec.add_dependency 'mruby-enum-ext', core: 'mruby-enum-ext'
   spec.add_dependency 'mruby-array-ext', core: 'mruby-array-ext'
-  spec.add_test_dependency 'mruby-enumerator', core: 'mruby-enumerator'
 end

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

@@ -269,10 +269,8 @@ assert("Hash#transform_keys") do
                h.transform_keys{|k| k+"!"})
   assert_equal({1 => 100, 2 => 200},
                h.transform_keys{|k|k.to_i})
-  assert_equal({"1.0" => 100, "2.1" => 200},
-               h.transform_keys.with_index{|k, i| "#{k}.#{i}"})
-  assert_equal(h, h.transform_keys!{|k|k.to_i})
-  assert_equal(h, {1 => 100, 2 => 200})
+  assert_same(h, h.transform_keys!{|k|k.to_i})
+  assert_equal({1 => 100, 2 => 200}, h)
 end
 
 assert("Hash#transform_values") do
@@ -281,9 +279,7 @@ assert("Hash#transform_values") do
                h.transform_values{|v| v * v + 1})
   assert_equal({a: "1", b: "2", c: "3"},
                h.transform_values{|v|v.to_s})
-  assert_equal({a: "1.0", b: "2.1", c: "3.2"},
-               h.transform_values.with_index{|v, i| "#{v}.#{i}"})
-  assert_equal(h, h.transform_values!{|v|v.to_s})
+  assert_same(h, h.transform_values!{|v|v.to_s})
   assert_equal({a: "1", b: "2", c: "3"}, h)
 end