Add to_s method to Beer class and use it in the new rating form

Signed-off-by: Janne Haapsaari <haaja@iki.fi>
Redirect to list of all beers after succesfully adding a beer

Signed-off-by: Janne Haapsaari <haaja@iki.fi>
Implement to_s in Brewery class

Signed-off-by: Janne Haapsaari <haaja@iki.fi>
Select brewery from dropdown list

Signed-off-by: Janne Haapsaari <haaja@iki.fi>
Select style from drop down list

Signed-off-by: Janne Haapsaari <haaja@iki.fi>