Better way to reference context manager

Signed-off-by: Michal Čihař <michal@cihar.com>
Fix unicode method for vote

Signed-off-by: Michal Čihař <michal@cihar.com>
These should raise only KeyError

Signed-off-by: Michal Čihař <michal@cihar.com>
Move calculation to better place

Signed-off-by: Michal Čihař <michal@cihar.com>