Revert "Check for spree.login_path, not spree.spree_login_path in unauthorized redirect"

This reverts commit fcda08552036b20a9866b189bd0e74ea8bef1830.

This causes the build to break:
http://ci.spreecommerce.com/viewLog.html?buildId=1533&buildTypeId=bt5&tab=buildLog

This is due to payment_required? calling update_totals all the time.
Revert "Don't require payment methods if payment isn't required"

This reverts commit 318b820114d6d631e9be6ddb500e6a234612407f.

This is causing build breakages:

http://ci.spreecommerce.com/viewLog.html?buildId=1533&buildTypeId=bt5&tab=buildLog

payment_required? is calling update_totals, which causes a massive callback
chain and ultimately results in these tests failing