New: add controller welcome,user_log_fact
New: welcome#index
New: install bootstrap
Merge branch 'bootstrap' into feature/show_analytics
install font-awesome
seed user log
New: add UserLogFact.activate_user_per_month
move js to jsfile
New: add ActivateUserPerMonthSerializer
New: add result.activate_user_per_month line chart
Merge branch 'active_model_serializers' into feature/show_analytics
New: add user. action_by_month
New: add ActionByMonthSerializer
Merge branch 'feature/show_analytics'
install chart.js through bower
require chartjs
Merge branch 'chartjs'