Merge branch 'hotfix/up_coverage'

* hotfix/up_coverage:
  remove somthing
  remove unused functions from lacture model
  add test
  remove unused strings
Merge branch 'develop'
fix empty lectures
fix lectures 2.0 link
remove lectures from account
remove link i will come to stachka
some rename account/lectures link to mailto
rename root_path to welcome_index_path
add not paid event
fix locales of state
Merge remote-tracking branch 'origin/feature/pay_for_conference' into feature/pay_for_conference
Merge remote-tracking branch 'origin/feature/pay_for_conference' into feature/pay_for_conference
fix merge conflict