Check if payment is required before checking if there are any payments in ensure_valid_state
Deleted shipping methods are now accessible from a shipping rate

Fixes #3829
Ensure Coupon Applicator actually, you know, APPLIES COUPONS.
Add exceptions for blank records in tax categories migration

Fixes #4204
Added Regexp tab matching
Catch exceptions within Spree::Stock::Estimator#shipping_methods and log them

Fixes #4227
Import variables using full-path, so that an overridden file in the application will be loaded

Fixes #3415
Show advice to run bundle exec rake test_app if dummy/config/environment fails to load
Added missing index for variant_id and currency on spree_prices

Fixes #4232