show event menu bar.
add tabs_on_rails gem.
used new layout in checkin view
Optimization code #350
fixed rspec error.
Merge pull request #360 from saberma/add_event_menu_bar

显示活动管理菜单
email participant fix #350
email participant job 2 fix #350
test code for email participant fix #350
merge with newest master code #350
Optimization code2 #350
modify the index view and css
Fix slim 2.0 compatible warnings
Merge branch 'fix-slim-2.0-warnings'
Extract Event#upcoming to ease test
Rename reminder_participants -> remind_participants
Merge branch 'feature/350-email-participant'
[#355] add BaiduMap preview in new/edit event page
#355 Refactor move inline javacript to external js file
#355 Display baidu map on event show page
#355 add initializers file for baidu map, make it posoible for user to enable/disable baidu map throught config key