Force select2-rails to 3.2.1

select2-rails 3.2.2 breaks all capybara helpers in Spree that depends on
the label tag for attribute. e.g.

    <%= label_tag :add_variant_id, Spree.t(:name_or_sku) %>

    Instead of:

    <label for="s2id_add_variant_id">some text</label>

    will generate:

    <label for="s2id_autogen1">some text</label>

see https://github.com/ivaynberg/select2/commit/519070b11da9347cf1542d26fc59a83b0c3fd934

wtf select2 ..

Most of backend request specs were failing due to this
Only reload shipment if it's persisted [Fixes #3037]

Fix remaining backend failing specs
Add index on spree_variants.sku [Fixes #3038]
display stock_transfer number on show page
missing translation for stock transfer show
Prevent adding items without stock via admin UI [Fixes #3041]

If stock item on hand is 0 and it doesn't allow backordering admin
shouldn't be able to add the product

[Fixes #2998]
Taxon edit form layout tidyup

Fixes #3042
Consolidate spree/order attributes for coupon_code
Add backorderable default config to StockLocation [Fixes #3045]

Stock items backorderable values will be set according to this config
every time either a variant or a stock location is created
Add propagate variants config to StockLocation [Fixes #3050]

Every time either a new stock location or new variant is created the
stock_location##propagate_all_variants value will be checked to decide
whether new stock items should be created for the new stock location or
variant
Respect CanCan.
Update Spree versions listed in README
Allow users to easily override zipcode validation

Just like it's already done with the phone field

[Fixes #3065]
[Fixes #3073]
remove unused variable redefinition [Fixes #3072]
Use Spree.url() to build taxonomies jstree urls

URLs were hardcoded which caused errors when users mounted Spree in a
path other then "/"

[Fixes #3070] [Fixes #3071]
master branch is now 2.1.0.beta
Remove legacy comment from order model [Fixes #3063]
Changed required RubyGems version to 1.8.23 so that Heroku can host it
[Fixes #3077]
Create a CHANGELOG file for each Spree component

It should help us to have a detailed idea of what changes between
versions. Both community and core developers could add an entry for
every relevant change. e.g. deprecated methods, relevant API
improvements, fixes.

Fixes #3062
Adding i18n values to English Locale