Added the first part for calculators specs
crafted a small perk for cleaning the db without losing the seeded data
Crafting test app
fixing load_data
Finished a partial version of the test suite
fixing calculator
Fixed calculator logic, and added methods to context and rate
Merge remote-tracking branch 'origin/2-3-stable' into 2-4-stable

Conflicts:
	app/models/spree/calculator_flight.rb