reload I18n as we are defining `:ts` locale

fix build- see https://travis-ci.org/rails/rails/jobs/27578159#L2913.

actionview/test/template/number_helper_test.rb

@@ -114,6 +114,8 @@ class NumberHelperTest < ActionView::TestCase
     I18n.backend.store_translations 'ts',
       :custom_units_for_number_to_human => {:mili => "mm", :centi => "cm", :deci => "dm", :unit => "m", :ten => "dam", :hundred => "hm", :thousand => "km"}
     assert_equal "1.01 cm", number_to_human(0.0101, :locale => 'ts', :units => :custom_units_for_number_to_human)
+  ensure
+    I18n.reload!
   end
 
   def test_number_helpers_outputs_are_html_safe