fixed comments test fixtures due to new last_activity_at method

Author: Oaphi

test/fixtures/comments.yml

@@ -4,13 +4,17 @@ one:
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: normal
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 two:
   user: standard_user
   post: question_two
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: normal_two
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 deleted:
   user: standard_user
@@ -19,38 +23,50 @@ deleted:
   deleted: true
   community: sample
   comment_thread: normal
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 deleted_thread:
   user: standard_user
   post: question_one
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: deleted
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 locked_thread:
   user: standard_user
   post: question_one
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: locked
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 archived_thread:
   user: standard_user
   post: question_one
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: archived
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 on_answer:
   user: standard_user
   post: answer_one
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: on_answer
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z
 
 new_user_on_own_post:
   user: basic_user
   post: new_user_question
   content: ABCDEF GHIJKL MNOPQR
   community: sample
   comment_thread: new_user_on_own_post
+  created_at: 2020-01-01T00:00:00.000000Z
+  updated_at: 2021-01-01T00:00:00.000000Z