Fix wrapping environment label with admin gem bump

Pull in fix for wrapping environment label.
See https://github.com/alphagov/govuk_admin_template/pull/54

## Example of the bug
![screen shot 2014-12-04 at 16 41 38](https://cloud.githubusercontent.com/assets/319055/5301921/783589e2-7bd4-11e4-8fdb-933666be46c8.png)