Add initial VariantOverride model with price lookup
Add simple variant proxy
Add ProductProxy which wraps the product's variants in VariantProxys
Comment proxy classes
Add have_select2 capybara matcher
Show list of hubs to select for managing variant overrides
have_select2 can test for an exact set of options
Do not show producers in hubs list
User can select a hub
Add indexer service (equivalent of Dereferencer, but named more accurately)
Display products in table
Extract fetch-by-page from BPE to service
Extract Spree API authorisation to service
Incrementally load products
Do not show Override Variants tab - hide this until feature is ready