fix bug that happen when cannot parse content of announcement
fix bug in update_announcements() of spider
fix bug that SpiderManager get the wrong url_id, start to refactor spider part
remove the ugly SpiderManager. try to fix the bug that in get_announcements
not fix bug yet. now start to build activity module
add activity, not test yet
finishe activity
amend code style
finish spider part
amend code style
fix bug that update can't stop by stop_mark
amend implementation by using xpath
get_announcement_content
replace the former function get_announcement with search_announcements, and rename some function
Merge remote-tracking branch 'upstream/develop' into develop
amend implementation, start to add template
amend match in lecture
remove unnecessary function
add css image
add css images for spider lecture