* Switch Poison to Jason
* generate-samples.sh
* Finalize Poison -> Jason switch
* parse date-time values to Elixir DateTime
* improve formatting in various places, so there's less changes by `mix
format` later
* fix Java version in flake.nix
* Use List.delete/2 instead of Enum.reject/2 for performance reasons
* mix format test/*
* Install dialyxir and fix reported issues
* Fix RequestBuilder.decode/2 hardcoded module name
* Update docs
* Revert changes to API spec (HTTP -> HTTPS)
* Revert uneeded change to Elixir code generator
* Use HTTP in Elixir tests
HTTPS doesn't work for folks who setup petstore.swagger.io as described
in docs/faq-contributing.md.
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Co-authored-by: Wojciech Piekutowski <wojciech@piekutowski.net>
