added test hash to reviewer email subject line

test/mailers/reviewer_mailer_test.rb

@@ -6,6 +6,7 @@ class ReviewerMailerTest < ActionMailer::TestCase
     candidate = candidates :dawn
     mail = ReviewerMailer.candidate_submission candidate
     assert_match "Results", mail.subject
+    assert_match candidate.test_hash, mail.subject
     assert_equal candidate.quiz.reviewers.map(&:email), mail.to
     assert_equal [ENV["default_mail_from"]], mail.from
     assert_match candidate.test_hash, mail.body.encoded