2.2.0

• Add missing tax_info attributes to customer
• Ease up on hackney dependency
• New Feature: Add Recipient endpoint
• Expand test matrix with Elixir 1.7
• Convert discount responses to a struct
• Add name to Stripe.Coupon
• Add unit_label attribute to Stripe.Product
• Add params to Stripe.Subscription and Stripe.Invoice endpoints
• Add active attribute to Stripe.Plan
• Add source_url to mix.exs
• Improved formatting (using mix format in some files
• Improved webhook documentation