add failling test for https://github.com/spree/spree/issues/2823

Fixes #2869
Bump selenium-webdriver to 2.32.0
Pass args to provider method with send in Spree::Gateway#method_missing

Change-Id: Iff96153001cb3237b7a6cfe4bec3c25e086ec784

Fixes #2872
Scope stock locations by ability.

Fixes #2871
Replace lazily_find_element with a have_css matcher to automatically wait.

Fixes #2873
[api] Don't set taxon.parent_id in Api::TaxonsController if parameters contain parent_id

Fixes #2757
Fix issue where multiple ids were being chained to the end of a URL when a
taxon was edited.