AO3-6835 Create change_email mailer preview #4670

Job	Run time
rake db:otwseed	1m 14s
rspec spec/controllers	11m 47s
rspec spec/models	5m 44s
rspec --exclude-pattern 'spec/{controllers,models}/*/.rb'	7m 35s
cucumber features/admins	5m 55s
cucumber features/bookmarks	4m 55s
cucumber features/collections	5m 53s
cucumber features/comments_and_kudos	6m 47s
cucumber features/gift_exchanges	6m 54s
cucumber features/importing	2m 44s
cucumber features/other_a	11m 25s
cucumber features/other_b	6m 54s
cucumber features/prompt_memes_a	3m 59s
cucumber features/prompt_memes_b	3m 30s
cucumber features/prompt_memes_c	4m 52s
cucumber features/search	6m 31s
cucumber features/tag_sets	3m 18s
cucumber features/tags_and_wrangling	6m 5s
cucumber features/users	4m 46s
cucumber features/works	13m 15s
	2h 4m 3s

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