- delete logs table and all related stuff
- delete devices/last_data
- locale = en in RailsAdmin

Signed-off-by: Csanad <erdos@ecs-solutions.hu>
devices - new layout

Signed-off-by: Csanad <erdos@ecs-solutions.hu>
devices/index.html.erb => haml

Signed-off-by: Csanad <erdos@ecs-solutions.hu>