2.2.3

• Configurable json serializer - You can now use Jason instead of Poison
• Support for voiding invoices
• Use singular time units in System.system_time/1
• Expanded configuration options
• Add invoice settings to customer/invoice objects
• Upgrade to 2018-11-08 Stripe API
• Fixed bug in Usage.retrieve
• Add elixir 1.8 to test matrix
• [Add authorization header api key to deauthorization endpoint]((#465)
• Add support for idempotent post requests
• Support new Checkout flow
• Add receipt_url to the return Charge data
• Fixed some bugs in Review struct fields
• Add basic support for payment intents
• Make client_secret optional
• Update hackney requirement to 1.15
• Upgrade to ex doc 0.20
• Upgrade stripe mock to 0.55
• Remove unused Bypass dependency
• Implement assert_stripe_requested/3 test helper
• Misc documentation improvements