- Extract to Devise custom strategy
- Use `SSL_CLIENT_S_DN_CN` env variable instead of `SSL_CLIENT_S_DN` to
get ID card data
- Remove `database_authenticatable` strategy from `RegistrantUser`
Closes#1047
* Extract frequently used country_code and ident methods
* Refactor domain query
* Add contact query method
* Add adminstrated_domains query method. Name will most likely change
in the future developments
* Change registry locks integration test name