This commit adds a new database table user_roles to prepare for the
introduction of a voter management system. All existing enabled voters
are added to the VOTER role.
- switch from goose to github.com/rubenv/sql-migrate
- move assets (static, templates, migrations) to boardvoting package
- add generated boardvoting/assets.go
- remove unused static files from static directory
- add package db with db migration configuration
This commit switches from loggo to the more flexible go-logging
framework. Logs of severity INFO or higher are now written to a separate
boardvoting.log file.
Errors during execution of mail templates are now logged.
A reasoning for the vote result is now logged and put into the mail
notification when a decision is closed.
