upgrade ruby and rails

[#83585010]
add omniauth-google-oauth2

[#80824248]
add google authorization and logout routes

[#80824248]
update config.yml

[#80824248]
add google_auth_required method

[#80824248]
update session ctrl

[#80824248]
add session#logout

[#80824248]
add logout link to view

[#80824248]
add omniauth-google provider to initialiser

[#80824248]