rename the IncompleteReimbursement to be extactly what it is.
fix typo on api payments_controller#new
[backend] Hiding option values handle if object is not persisted

[backend] @option_type.option_values is always set. No need to verify it emptiness

[backend] Hiding the handle of option values if object is not persisted

Fixes #5617
Fixes #4836
Add actionable? to Promotion::Rules::Taxon

Fixes #5621
refs #4477
support callbacks on clear cache, support custom callbacks

Fixes #5623
enable houndci for PR's
add link to new s3 documentation in the heroku deployment guide

Closes #5641
Introduce DisplayMoney class mixin to clean up display_* method model logic.

There are a lot of model-level methods named display_ that just wrap a
numeric in a Spree::Money object. Rather than taking up space and mental
overhead in the models, this class mixin allows for defining of those
desired display_methods in a tidier way (with some configuration), in an effort to make some of
these models smaller and easier to reason about.

Closes #5640
Validate uniqueness of OptionType#name. Fixes #5629
Validate uniqueness of OptionValue#name. Fixes #5630
Sequence factories for uniqueness. refs #5629
Bump Rails.
reduce queries when running spree/stock specs

those should run over 40s faster now
Indexing the guest_token column on spree_orders

Closes #5648
Add .rubocop.yml

This is the default Hound ruby style config taken from:
https://github.com/thoughtbot/hound/blob/1f03cb64743765801a81c0f7ca9df64a448f1d48/config/style_guides/ruby.yml

These are the checks that Hound currently runs on every pull request.
This config allows people to run rubocop on their local boxes to see
what Hound is going to complain about when they push code.

Closes #5649
add rubocop to the common spree test and development dependencies.
add bullet to the sandbox Gemfile
point houndCI to our local rubocop.yml
set max line lenght to 100
prefer single quotes.
disable string literals, to much noise here.
Namespace eligibility validator like the rest.