Titling the model name in views generated by scaffold.
eg. rails g scaffold UserProfile will have in index.html.erb "Listing User Profiles"
rather than Listing user_profiles.
Extract out with_env_tz helper method.

It’s used at so many places that extracting it out into a helper file
is worth doing.
Merge pull request #15799 from zuhao/refactor_activesupport_time_zone_test_helpers

Extract out with_env_tz helper method.
Merge pull request #15795 from amitsuryavanshi/master

Titling the model name in views generated by scaffold.