add gem 'sequenced' and 'aasm'
add basic issue CRUD
add time picker to issues, update view
change module expressions
add issue css and modify the flow of user injection in issue create
add parser concern, modify view of issue, add img-round to avatar_tag
update ui, remove useless code
add time formatter and auto update event
fix the double quote
add html field to comments table
parse comment content before saving
add CommentPolicy
add CommentsController and routes
add CommentableConcern
include CommentableConcern in Issue model
update #show view
use sync on issue's view
add sync create to comments of issue
replace issue.content  with issue.html
add display of issue status